混凝土结构配筋设计中英文对照外文翻译文献
混凝土工艺中英文对照外文翻译文献
混凝土工艺中英文对照外文翻译文献混凝土工艺中英文对照外文翻译文献混凝土工艺中英文对照外文翻译文献(文档含英文原文和中文翻译) Concrete technology and developmentPortland cement concrete has clearly emerged as the material of choice for the construction of a large number and variety of structures in the world today. This is attributed mainly to low cost of materials and construction for concrete structures as well as low cost of maintenance.Therefore, it is not surprising that many advancements in concrete technology have occurred as a result of two driving forces, namely the speed of construction and the durability of concrete.During the period 1940-1970, the availability of high early strength portland cements enabled the use of high water content in concrete mixtures that were easy to handle. This approach, however, led to serious problems with durability of structures, especially those subjected to severe environmental exposures.With us lightweight concrete is a development mainly of the last twenty years.Concrete technology is the making of plentiful good concrete cheaply. It includes the correct choice of the cement and the water, and the right treatment of the aggregates. Those which are dug near by and therefore cheap, must be sized, washed free of clay or silt, and recombined in the correct proportions so as to make a cheap concrete which is workable at a low water/cement ratio, thus easily comoacted to a high density and therefore strong.It hardens with age and the process of hardening continues for a long time after the concrete has attained sufficient strength.Abrams’law, perhaps the oldest law of concrete technology, states that the strength of a concrete varies inversely with its water cement ratio. This means that the sand content (particularly the fine sand which needs much water) must be reduced so far as possible. The fact that the sand “drinks” large quantities of water can easily be established by mixing several batches of x kg of cement with y kg of stone and the same amount of water but increasing amounts of sand. However if there is no sand the concrete will be so stiff that it will be unworkable thereforw porous and weak. The same will be true if the sand is too coarse. Therefore for each set of aggregates, the correct mix must not be changed without good reason. This applied particularly to the water content.Any drinkable and many undrinkable waters can be used for making concrete, including most clear waters from the sea or rivers. It is important that clay should be kept out of the concrete. The cement if fresh can usually be chosen on the basis of the maker’s certificates of tensile or crushing tests, but these are always made with fresh cement. Where strength is important , and the cement at the site is old, it should be tested.This stress , causing breakage,will be a tension since concretes are from 9 to 11times as strong in compression as in tension, This stress, the modulus of rupture, will be roughly double the direct tensile breaking stress obtained in a tensile testing machine,so a very rough guess at the conpressive strength can be made by multiplying the modulus of rupture by 4.5. The method can be used in combination with the strength results of machine-crushed cubes or cylinders or tensile test pieces but cannot otherwise be regarded as reliable. With these comparisons,however, it is suitable for comparing concretes on the same site made from the same aggregates and cement, with beams cast and tested in the same way.Extreme care is necessary for preparation,transport,plating and finish of concrete in construction works.It is important to note that only a bit of care and supervision make a great difference between good and bad concrete.The following factors may be kept in mind in concreting works.MixingThe mixing of ingredients shall be done in a mixer as specified in the contract.Handling and ConveyingThe handling&conveying of concrete from the mixer to the place of final deposit shall be done as rapidly as practicable and without any objectionable separation or loss of ingredients.Whenever the length of haul from the mixing plant to the place of deposit is such that the concrete unduly compacts or segregates,suitable agitators shall be installed in the conveying system.Where concrete is being conveyed on chutes or on belts,the free fall or drop shall be limited to 5ft.(or 150cm.) unless otherwise permitted.The concrete shall be placed in position within 30 minutes of its removal from the mixer.Placing ConcreteNo concrete shall be placed until the place of deposit has been thoroughly inspected and approved,all reinforcement,inserts and embedded metal properly security in position and checked,and forms thoroughly wetted(expect in freezing weather)or oiled.Placing shall be continued without avoidable interruption while the section is completed or satisfactory construction joint made.Within FormsConcrete shall be systematically deposited in shallow layers and at such rate as to maintain,until the completion of the unit,a plastic surface approximately horizontal throughout.Each layer shall be thoroughly compacted before placing the succeeding layer.CompactingMethod. Concrete shall be thoroughly compacted by means of suitable tools during and immediately after depositing.The concrete shall be worked around all reinforcement,embedded fixtures,and into the comers of the forms.Every precaution shall be taken to keep the reinforcement and embedded metal in proper position and to prevent distortion.Vibrating. Wherever practicable,concrete shall be internally vibrated within the forms,or in the mass,in order to increase the plasticity as to compact effectively to improve the surface texture and appearance,and to facilitate placing of the concrete.Vibration shall be continued the entire batch melts to a uniform appearance and the surface just starts to glisten.A minute film of cement paste shall be discernible between the concrete and the form and around the reinforcement.Over vibration causing segregation,unnecessary bleeding or formation of laitance shall be avoided.The effect spent on careful grading, mixing and compaction of concrete will be largely wasted if the concrete is badly cured. Curing means keeping the concretethoroughly damp for some time, usually a week, until it has reached the desired strength. So long as concrete is kept wet it will continue to gain strength, though more slowly as it grows older.Admixtures or additives to concrete are materials arematerials which are added to it or to the cement so as to improve one or more of the properties of the concrete. The main types are:1. Accelerators of set or hardening,2. Retarders of set or hardening,3. Air-entraining agents, including frothing or foaming agents,4. Gassing agents,5. Pozzolanas, blast-furnace slag cement, pulverized coal ash,6. Inhibitors of the chemical reaction between cement and aggregate, which might cause the aggregate to expand7. Agents for damp-proofing a concrete or reducing its permeability to water,8. Workability agents, often called plasticizers,9. Grouting agents and expanding cements.Wherever possible, admixtures should be avouded, particularly those that are added on site. Small variations in the quantity added may greatly affect the concrete properties in an undesiraale way. An accelerator can often be avoided by using a rapid-hardening cement or a richer mix with ordinary cement, or for very rapid gain of strength, high-alumina cement, though this is very much more expensive, in Britain about three times as costly as ordinary Portland cement. But in twenty-four hours its strength is equal to that reached with ordinary Portland cement in thirty days.A retarder may have to be used in warm weather when a large quantity of concrete has to be cast in one piece of formwork, and it is important that the concrete cast early in the day does not set before the last concrete. This occurs with bridges when they are cast in place, and the formwork necessarily bends underthe heavy load of the wet concrete. Some retarders permanently weaken the concrete and should not be used without good technical advice.A somewhat similar effect,milder than that of retarders, is obtained with low-heat cement. These may be sold by the cement maker or mixed by the civil engineering contractor. They give out less heat on setting and hardening, partly because they harden more slowly, and they are used in large casts such as gravity dams, where the concrete may take years to cool down to the temperature of the surrounding air. In countries like Britain or France, where pulverized coal is burnt in the power stations, the ash, which is very fine, has been mixed with cement to reduce its production of heat and its cost without reducing its long-term strength. Up to about 20 per cent ash by weight of the cement has been successfully used, with considerable savings in cement costs.In countries where air-entraining cement cement can be bought from the cement maker, no air-entraining agent needs to be mixed in .When air-entraining agents draw into the wet cement and concrete some 3-8 percent of air in the form of very small bubbles, they plasticize the concrete, making it more easily workable and therefore enable the water |cement ratio to be reduced. They reduce the strength of the concrete slightly but so little that in the United States their use is now standard practice in road-building where heavy frost occur. They greatly improve the frost resistance of the concrete.Pozzolane is a volcanic ash found near the Italian town of Puzzuoli, which is a natural cement. The name has been given to all natural mineral cements, as well as to the ash from coal or the slag from blast furnaces, both of which may become cementswhen ground and mixed with water. Pozzolanas of either the industrial or the mineral type are important to civil engineers because they have been added to oridinary Portland cement in proportions up to about 20 percent without loss of strength in the cement and with great savings in cement cost. Their main interest is in large dams, where they may reduce the heat given out by the cement during hardening. Some pozzolanas have been known to prevent the action between cement and certain aggregates which causes the aggregate to expand, and weaken or burst the concrete.The best way of waterproof a concrete is to reduce its permeability by careful mix design and manufacture of the concrete, with correct placing and tighr compaction in strong formwork ar a low water|cement ratio. Even an air-entraining agent can be used because the minute pores are discontinuous. Slow, careful curing of the concrete improves the hydration of the cement, which helps to block the capillary passages through the concrete mass. An asphalt or other waterproofing means the waterproofing of concrete by any method concerned with the quality of the concrete but not by a waterproof skin.Workability agents, water-reducing agents and plasticizers are three names for the same thing, mentioned under air-entraining agents. Their use can sometimes be avoided by adding more cement or fine sand, or even water, but of course only with great care.The rapid growth from 1945 onwards in the prestressing of concrete shows that there was a real need for this high-quality structural material. The quality must be high because the worst conditions of loading normally occur at the beginning of the life of the member, at the transfer of stress from the steel to theconcrete. Failure is therefore more likely then than later, when the concrete has become stronger and the stress in the steel has decreased because of creep in the steel and concrete, and shrinkage of the concrete. Faulty members are therefore observed and thrown out early, before they enter the structure, or at least before it The main advantages of prestressed concrete in comparison with reinforced concrete are :①The whole concrete cross-section resists load. In reinforced concrete about half the section, the cracked area below the neutral axis, does no useful work. Working deflections are smaller.②High working stresses are possible. In reinforced concrete they are not usually possible because they result in severe cracking which is always ugly and may be dangerous if it causes rusting of the steel.③Cracking is almost completely avoided in prestressed concrete.The main disadvantage of prestressed concrete is that much more care is needed to make it than reinforced concrete and it is therefore more expensive, but because it is of higher quality less of it needs to be needs to be used. It can therefore happen that a solution of a structural problem may be cheaper in prestressed concrete than in reinforced concrete, and it does often happen that a solution is possible with prestressing but impossible without it.Prestressing of the concrete means that it is placed under compression before it carries any working load. This means that the section can be designed so that it takes no tension or very little under the full design load. It therefore has theoretically no cracks and in practice very few. The prestress is usually applied by tensioning the steel before the concrete in which it isembedded has hardened. After the concrete has hardened enough to take the stress from the steel to the concrete. In a bridge with abutments able to resist thrust, the prestress can be applied without steel in the concrete. It is applied by jacks forcing the bridge inwards from the abutments. This methods has the advantage that the jacking force, or prestress, can be varied during the life of the structure as required.In the ten years from 1950 to 1960 prestressed concrete ceased to be an experinmental material and engineers won confidence in its use. With this confidence came an increase in the use of precast prestressed concrete particularly for long-span floors or the decks of motorways. Whereever the quantity to be made was large enough, for example in a motorway bridge 500 m kong , provided that most of the spans could be made the same and not much longer than 18m, it became economical to usefactory-precast prestressed beams, at least in industrial areas near a precasting factory prestressed beams, at least in industrial areas near a precasting factory. Most of these beams are heat-cured so as to free the forms quickly for re-use.In this period also, in the United States, precast prestressed roof beams and floor beams were used in many school buildings, occasionally 32 m long or more. Such long beams over a single span could not possibly be successful in reinforced concrete unless they were cast on site because they would have to be much deeper and much heavier than prestressed concrete beams. They would certainlly be less pleasing to the eye and often more expensive than the prestressed concrete beams. These school buildings have a strong, simple architectural appeal and will be a pleasure to look at for many years.The most important parts of a precast prestressed concrete beam are the tendons and the concrete. The tendons, as the name implies, are the cables, rods or wires of steel which are under tension in the concrete.Before the concrete has hardened (before transfer of stress), the tendons are either unstressed (post-tensioned prestressing) or are stressed and held by abutments outside the concrete ( pre-tensioned prestressing). While the concrete is hardening it grips each tendon more and more tightly by bond along its full length. End anchorages consisting of plates or blocks are placed on the ends of the tendons of post-tensioned prestressed units, and such tendons are stressed up at the time of transfer, when the concrete has hardened sufficiently. In the other type of pretressing, with pre-tensioned tendons, the tendons are released from external abutments at the moment of transfer, and act on the concrete through bond or archorage or both, shortening it by compression, and themselves also shortening and losing some tension.Further shortening of the concrete (and therefore of the steel) takes place with time. The concrete is said to creep. This means that it shortens permanently under load and spreads the stresses more uniformly and thus more safely across its section. Steel also creeps, but rather less. The result of these two effects ( and of the concrete shrinking when it dries ) is that prestressed concrete beams are never more highly stressed than at the moment of transfer.The factory precasting of long prestressed concrete beams is likely to become more and more popular in the future, but one difficulty will be road transport. As the length of the beam increases, the lorry becomes less and less manoeuvrable untileventually the only suitable time for it to travel is in the middle of the night when traffic in the district and the route, whether the roads are straight or curved. Precasting at the site avoids these difficulties; it may be expensive, but it has often been used for large bridge beams.混凝土工艺及发展波特兰水泥混凝土在当今世界已成为建造数量繁多、种类复杂结构的首选材料。
钢筋混凝土中英文对照外文翻译文献
中英文资料对照外文翻译目录1 中文翻译 (1)1.1钢筋混凝土 (1)1.2土方工程 (2)1.3结构的安全度 (3)2 外文翻译 (6)2.1 Reinforced Concrete (6)2.2 Earthwork (7)2.3 Safety of Structures (9)1 中文翻译1.1钢筋混凝土素混凝土是由水泥、水、细骨料、粗骨料（碎石或；卵石）、空气，通常还有其他外加剂等经过凝固硬化而成。
将可塑的混凝土拌合物注入到模板内，并将其捣实，然后进行养护，以加速水泥与水的水化反应，最后获得硬化的混凝土。
其最终制成品具有较高的抗压强度和较低的抗拉强度。
其抗拉强度约为抗压强度的十分之一。
因此，截面的受拉区必须配置抗拉钢筋和抗剪钢筋以增加钢筋混凝土构件中较弱的受拉区的强度。
由于钢筋混凝土截面在均质性上与标准的木材或钢的截面存在着差异，因此，需要对结构设计的基本原理进行修改。
将钢筋混凝土这种非均质截面的两种组成部分按一定比例适当布置，可以最好的利用这两种材料。
这一要求是可以达到的。
因混凝土由配料搅拌成湿拌合物，经过振捣并凝固硬化，可以做成任何一种需要的形状。
如果拌制混凝土的各种材料配合比恰当，则混凝土制成品的强度较高，经久耐用，配置钢筋后，可以作为任何结构体系的主要构件。
浇筑混凝土所需要的技术取决于即将浇筑的构件类型，诸如：柱、梁、墙、板、基础，大体积混凝土水坝或者继续延长已浇筑完毕并且已经凝固的混凝土等。
对于梁、柱、墙等构件，当模板清理干净后应该在其上涂油，钢筋表面的锈及其他有害物质也应该被清除干净。
浇筑基础前，应将坑底土夯实并用水浸湿6英寸，以免土壤从新浇的混凝土中吸收水分。
一般情况下，除使用混凝土泵浇筑外，混凝土都应在水平方向分层浇筑，并使用插入式或表面式高频电动振捣器捣实。
必须记住，过分的振捣将导致骨料离析和混凝土泌浆等现象，因而是有害的。
水泥的水化作用发生在有水分存在，而且气温在50°F以上的条件下。
桩基础、钢筋混凝土和钢筋混凝土结构-外文翻译
Piles, Reinforced Concreteand Reinforced Concrete StructuresPilesPiles are structural members of timber, concrete, and/or steel, used to transmit surface loads to lower levels in the soil mass. This may be by vertical distribution of the load along the pile shaft or a direct application of load to the lower stratum through the pile point. A vertical distribution of the load is made using a friction pile and a direct load application is made by a point, or end-bearing pile. This distinction of piles is purely one of convenience since all piles function as a combination of side resistance and point bearing except when the pile penetrates an extremely soft soil to a solid base.Piles are commonly used: (1) To carry the superstructure loads into or through a soil stratum. Both vertical and lateral loads may be involved. (2) To resist uplift, or overturning, forces as for basement mats below the water table or to support tower legs subjected to overturning. (3) To compact loose, cohesionless deposits through a combination of pile volume displacement and driving vibrations. These piles may be later pulled. (4) To control settlements when spread footings or a mat is on a marginal soil or is underlain by a highly compressible stratum. (5) To stiffen the soil beneath machine foundations to control both amplitudes of vibration and the natural frequency of the system. (6) As an additional safety factor beneath bridge abutments and/or piers, particularly if scour is a potential problem. (7) In offshore construction to transmit loads above the water surface through the water and into the underlying soil. This is a case of partially embedded piling subjected to vertical( and buckling) as well as lateral loads.Piles are sometimes used to control earth movements (as landslides). The reader should note that power poles and many outdoor sign poles may be considered as partially embedded piles subject to lateral loads. Vertical loads may not be significant, although buckling may require investigation for very tall members.A pile foundation is more expensive than spread footings and likely to be more expensive than a mat. In any case great care should be exercised in determing the soil properties at the site for the depth of possible interest so that it can be accurately determined that a pile foundation is needed and, if so, that neither an excessive number nor lengths are specified. A cost analysis should be made to determine whether a mat or piles, in particular the type (steel, concrete, etc.), are more economical. In those cases where piles are used to control the settlement at marginal soil sites, care should be taken to utilize both the existing ground and the piles in parallel so that a minimum number are required.Piles are inserted into the soil via a number of methods: (1) Driving with a steady succession of blows on the top of the pile using a pile hammer. This produces both considerable noise and vibrations which may be disallowed by local codes or environmental agencies and, of course, may damage adjacent property. (2) Driving using a vibratory device attached to the top of the pile. This is usually a relatively quiet method and driving vibrations may not be excessive. The method is more applicable in deposits with little cohesion. (3) Jacking the pile. This is more applicable for short stiff members. (4) Drilling a hole and either inserting a pileinto it or, more common, filling the cavity with concrete which produces a pile upon hardening. Reinforced ConcretePlain concrete is formed a hardened mixture of cement, water, fine aggregate, coarse aggregate (crushed stone or gravel), air, and often other admixtures. The plastic mix is placed and consolidated in the formwork, then cured to facilitate the acceleration of the chemical hydration reaction of the cement/water mix, resulting in hardened concrete. The finished product has high compressive strength, and low resistance to tension, such that its tensile strength is approximately one tenth of its compressive strength. Consequently, tensile and shear reinforcement in the tensile regions of sections has to be provided to compensate for the weak tension regions in the reinforced concrete element.It is this deviation in the composition of a reinforced concrete section from the homogeneity of standard wood or steel sections that requires a modified approach to the basic principles of structural design. The two components of the heterogeneous reinforced concrete section are to be so arranged and proportioned that optimal use is made of the materials involved. This is possible because concrete can easily be given any desired shape by placing and compacting the wet mixture of the constituent ingredients into suitable forms in which the plastic mass hardens. If the various ingredients are properly proportioned,the finished product becomes strong, durable, and ,in combination with the reinforcing bars, adaptable for use as main members fo any structural system.The techniques necessary for placing concrete depend on the type of member to be cast: that is, whether it is a column, a beam, a wall, a slab, a foundation, a mass concrete dam, or an extention of previously placed and hardened concrete. For beams, columns, and walls, the forms should be well oiled after cleaning them, and the reinforcement should be cleared of rust and other harmful materials. In foundations, the earth should be compacted and thoroughly moistened to about 6in.in depth to avoid absorption of the moisture present in the wet concrete. Concrete should always be placed in horizontal layers which are compacted by means of high frequency power –driven vibrators of either the immersion or external type, as the case requires, unless it is placed by pumping. It must be kept in mind, however, that over vibration can be harmful since it could cause segregation of the aggregate and bleeding of the concrete.Hydration of the cement takes place in the presence of moisture at temperatures above 50℉.It is necessary to maintain such a condition in order that the chemical hydration reaction can take place. If drying is too rapid, surface cracking takes place. This would result in reduction of concrete strength due to cracking as well as the failure to attain full chemical hydration.It is clear that a large number of parameters have to be dealt with in proportioning a reinforced concrete element, such as geometrical width, depth, area of reinforcement, steel strain, concrete strain, steel stress, and so on. Consequently, trial and adjustment is necessary in the choice of concrete sections, with assumptions based on conditions at site, availability of the constituent materials, particular demands of the owners, architectural and headroom requirements, the applicable codes, and environmental conditions. Such an array of parameters has to be considered because of the fact that reinforced concrete is often a site-constructed composite, in contrast to the standard mill-fabricated beam and column sections in steel structures.Reinforced Concrete StructuresReinforced concrete systems are composed of a variety of concrete structural elements that, when synthesized, produce a total system. The components can be broadly classified into: floor slabs, beams, columns, walls, and foundations.Floor Slabs Floor slabs are the main horizontal elements that transmit the moving live loads as well as the stationary dead loads to the vertical framing supports of a structure. They can be proportioned such that they act in one direction (one-way slabs) or proportioned so that they act in two perpendicular direction (two-way slabs).Beams Beams are the structural elements that transmit the loads from floor slabs to vertical supporting columns. They are normally cast monolithically with the slabs and are structurally reinforced on one face, the lower tension side, or both the top and bottom faces. As they are cast monolithically with the slab, they form a T-beam section for interior beams or an L beam at the building exterior, as seen in Fig.2.Columns The vertical elements support the structural floor system. They are compression members subjected in most cases to both bending and axial load, and are of major importance in the safety considerations of any structure. If a structural system is also composed of horizontal compression members, such members would be considered as beam-columns.Walls Walls are the vertical enclosures for building frames. They are not usually or necessarily made of concrete but of any material that aesthetically fulfills the form and functional needs of the structural system. Additionally, structural concrete walls are often necessary as foundation walls, stairwell walls, and shear walls that resist horizontal wind loads and earthquake-induced loads.Foundations Foundations are the structural concrete elements that transmit the weight of the superstructure to the supporting soil. They could be in many forms, the simplest being the isolated footing shown in Fig.2. It can be viewed as an inverted slab transmitting a distributed load from the soil to the column.桩基础、钢筋混凝土和钢筋混凝土结构桩基础桩是由木材、混凝土和（或）钢制成的结构构件，被用来把荷载传递到土体的较深处。
混凝土工艺中英文对照外文翻译文献
混凝土工艺中英文对照外文翻译文献混凝土工艺中英文对照外文翻译文献(文档含英文原文和中文翻译)Concrete technology and developmentPortland cement concrete has clearly emerged as the material of choice for the construction of a large number and variety of structures in the world today. This is attributed mainly to low cost of materials and construction for concrete structures as well as low cost of maintenance.Therefore, it is not surprising that many advancements in concrete technology have occurred as a result of two driving forces, namely the speed of construction and the durability of concrete.During the period 1940-1970, the availability of high early strength portland cements enabled the use of high water content in concrete mixtures that were easy to handle. This approach, however, led to serious problems with durability of structures, especially those subjected to severe environmental exposures.With us lightweight concrete is a development mainly of the last twenty years.Concrete technology is the making of plentiful good concrete cheaply. It includes the correct choice of the cement and the water, and the right treatment of the aggregates. Those which are dug near by and therefore cheap, must be sized, washed free of clay or silt, and recombined in the correct proportions so as to make a cheap concrete which is workable at a low water/cement ratio, thus easily comoacted to a high density and therefore strong.It hardens with age and the process of hardening continues for a long time after the concrete has attained sufficient strength.Abrams’law, perhaps the oldest law of concrete technology, states that the strength of a concrete varies inversely with its water cement ratio. This means that the sand content (particularly the fine sand which needs much water) must be reduced so far as possible. The fact that the sand “drinks” large quantities of water can easily be established by mixing several batches of x kg of cement with y kg of stone and the same amount of water but increasing amounts of sand. However if there is no sand the concrete will be so stiff that it will be unworkable thereforw porous and weak. The same will be true if the sand is too coarse. Therefore for each set of aggregates, the correct mix must not be changed without good reason. This applied particularly to the water content.Any drinkable and many undrinkable waters can be used for making concrete, including most clear waters from the sea or rivers. It is important that clay should be kept out of the concrete. The cement if fresh can usually be chosen on the basis of the maker’s certificates of tensile or crushing tests, but these are always made with fresh cement. Where strength is important , and the cement at the site is old, it should be tested.This stress , causing breakage,will be a tension since concretes are from 9 to 11times as strong in compression as in tension, This stress, the modulus of rupture, will be roughly double the direct tensile breaking stress obtained in a tensile testing machine,so a very rough guess at the conpressive strength can be made by multiplying the modulus of rupture by 4.5. The method can be used in combination with the strength results of machine-crushed cubes or cylinders or tensile test pieces but cannot otherwise be regarded as reliable. With these comparisons, however, it is suitable for comparing concretes on the same site made from the same aggregates and cement, with beams cast and tested in the same way.Extreme care is necessary for preparation,transport,plating and finish of concrete in construction works.It is important to note that only a bit of care and supervision make a great difference between good and bad concrete.The following factors may be kept in mind in concreting works.MixingThe mixing of ingredients shall be done in a mixer as specified in the contract.Handling and ConveyingThe handling&conveying of concrete from the mixer to the place of final deposit shall be done as rapidly as practicable and without any objectionable separation or loss of ingredients.Whenever the length of haul from the mixing plant to the place of deposit is such that the concrete unduly compacts or segregates,suitable agitators shall be installed in the conveying system.Where concrete is being conveyed on chutes or on belts,the free fall or drop shall be limited to 5ft.(or 150cm.) unless otherwise permitted.The concrete shall be placed in position within 30 minutes of its removal from the mixer.Placing ConcreteNo concrete shall be placed until the place of deposit has been thoroughly inspected and approved,all reinforcement,inserts and embedded metal properly security in position and checked,and forms thoroughly wetted(expect in freezing weather)or oiled.Placing shall be continued without avoidable interruption while the section is completed or satisfactory construction joint made.Within FormsConcrete shall be systematically deposited in shallow layers and at such rate as to maintain,until the completion of the unit,a plastic surface approximately horizontal throughout.Each layer shall be thoroughly compacted before placing the succeeding layer.CompactingMethod. Concrete shall be thoroughly compacted by means of suitable tools during and immediately after depositing.The concrete shall be worked around all reinforcement,embedded fixtures,and into the comers of the forms.Every precaution shall be taken to keep the reinforcement and embedded metal in proper position and to prevent distortion.Vibrating. Wherever practicable,concrete shall be internally vibrated within the forms,or in the mass,in order to increase the plasticity as to compact effectively to improve the surface texture and appearance,and to facilitate placing of the concrete.Vibration shall be continued the entire batch melts to a uniform appearance and the surface just starts to glisten.A minute film of cement paste shall be discernible between the concrete and the form and around the reinforcement.Over vibration causing segregation,unnecessary bleeding or formation of laitance shall be avoided.The effect spent on careful grading, mixing and compaction of concrete will be largely wasted if the concrete is badly cured. Curing means keeping the concretethoroughly damp for some time, usually a week, until it has reached the desired strength. So long as concrete is kept wet it will continue to gain strength, though more slowly as it grows older.Admixtures or additives to concrete are materials are materials which are added to it or to the cement so as to improve one or more of the properties of the concrete. The main types are:1. Accelerators of set or hardening,2. Retarders of set or hardening,3. Air-entraining agents, including frothing or foaming agents,4. Gassing agents,5. Pozzolanas, blast-furnace slag cement, pulverized coal ash,6. Inhibitors of the chemical reaction between cement and aggregate, which might cause the aggregate to expand7. Agents for damp-proofing a concrete or reducing its permeability to water,8. Workability agents, often called plasticizers,9. Grouting agents and expanding cements.Wherever possible, admixtures should be avouded, particularly those that are added on site. Small variations in the quantity added may greatly affect the concrete properties in an undesiraale way. An accelerator can often be avoided by using a rapid-hardening cement or a richer mix with ordinary cement, or for very rapid gain of strength, high-alumina cement, though this is very much more expensive, in Britain about three times as costly as ordinary Portland cement. But in twenty-four hours its strength is equal to that reached with ordinary Portland cement in thirty days.A retarder may have to be used in warm weather when a large quantity of concrete has to be cast in one piece of formwork, and it is important that the concrete cast early in the day does not set before the last concrete. This occurs with bridges when they are cast in place, and the formwork necessarily bends under the heavy load of the wet concrete. Some retarders permanently weaken the concrete and should not be used without good technical advice.A somewhat similar effect,milder than that of retarders, is obtained with low-heat cement. These may be sold by the cement maker or mixed by the civil engineering contractor. They give out less heat on setting and hardening, partly because they harden more slowly, and they are used in large casts such as gravity dams, where the concrete may take years to cool down to the temperature of the surrounding air. In countries like Britain or France, where pulverized coal is burnt in the power stations, the ash, which is very fine, has been mixed with cement to reduce its production of heat and its cost without reducing its long-term strength. Up to about 20 per cent ash by weight of the cement has been successfully used, with considerable savings in cement costs.In countries where air-entraining cement cement can be bought from the cement maker, no air-entraining agent needs to be mixed in .When air-entraining agents draw into the wet cement and concrete some 3-8 percent of air in the form of very small bubbles, they plasticize the concrete, making it more easily workable and therefore enable the water |cement ratio to be reduced. They reduce the strength of the concrete slightly but so little that in the United States their use is now standard practice in road-building where heavy frost occur. They greatly improve the frost resistance of the concrete.Pozzolane is a volcanic ash found near the Italian town of Puzzuoli, which is a natural cement. The name has been given to all natural mineral cements, as well as to the ash from coal or the slag from blast furnaces, both of which may become cements when ground and mixed with water. Pozzolanas of either the industrial or the mineral type are important to civil engineers because they have been added to oridinary Portland cement in proportions up to about 20 percent without loss of strength in the cement and with great savings in cement cost. Their main interest is in large dams, where they may reduce the heat given out by the cement during hardening. Some pozzolanas have been known to prevent the action between cement and certain aggregates which causes the aggregate to expand, and weaken or burst the concrete.The best way of waterproof a concrete is to reduce its permeability by careful mix design and manufacture of the concrete, with correct placing and tighr compaction in strong formwork ar a low water|cement ratio. Even an air-entraining agent can be used because the minute pores are discontinuous. Slow, careful curing of the concrete improves the hydration of the cement, which helps to block the capillary passages through the concrete mass. An asphalt or other waterproofing means the waterproofing of concrete by any method concerned with the quality of the concrete but not by a waterproof skin.Workability agents, water-reducing agents and plasticizers are three names for the same thing, mentioned under air-entraining agents. Their use can sometimes be avoided by adding more cement or fine sand, or even water, but of course only with great care.The rapid growth from 1945 onwards in the prestressing of concrete shows that there was a real need for this high-quality structural material. The quality must be high because the worst conditions of loading normally occur at the beginning of the life of the member, at the transfer of stress from the steel to the concrete. Failure is therefore more likely then than later, when the concrete has become stronger and the stress in the steel has decreased because of creep in the steel and concrete, and shrinkage of the concrete. Faulty members are therefore observed and thrown out early, before they enter the structure, or at least before it The main advantages of prestressed concrete in comparison with reinforced concrete are :①The whole concrete cross-section resists load. In reinforced concrete about half the section, the cracked area below the neutral axis, does no useful work. Working deflections are smaller.②High working stresses are possible. In reinforced concrete they are not usually possible because they result in severe cracking which is always ugly and may be dangerous if it causes rusting of the steel.③Cracking is almost completely avoided in prestressed concrete.The main disadvantage of prestressed concrete is that much more care is needed to make it than reinforced concrete and it is therefore more expensive, but because it is of higher quality less of it needs to be needs to be used. It can therefore happen that a solution of a structural problem may be cheaper in prestressed concrete than in reinforced concrete, and it does often happen that a solution is possible with prestressing but impossible without it.Prestressing of the concrete means that it is placed under compression before it carries any working load. This means that the section can be designed so that it takes no tension or very little under the full design load. It therefore has theoretically no cracks and in practice very few. The prestress is usually applied by tensioning the steel before the concrete in which it is embedded has hardened. After the concrete has hardened enough to take the stress from the steel to the concrete. In a bridge with abutments able to resist thrust, the prestress can be applied without steel in the concrete. It is applied by jacks forcing the bridge inwards from the abutments. This methods has the advantage that the jacking force, or prestress, can be varied during the life of the structure as required.In the ten years from 1950 to 1960 prestressed concrete ceased to be an experinmental material and engineers won confidence in its use. With this confidence came an increase in the use of precast prestressed concrete particularly for long-span floors or the decks of motorways. Whereever the quantity to be made was large enough, for example in a motorway bridge 500 m kong , provided that most of the spans could be made the same and not much longer than 18m, it became economical to usefactory-precast prestressed beams, at least in industrial areas near a precasting factory prestressed beams, at least in industrial areas near a precasting factory. Most of these beams are heat-cured so as to free the forms quickly for re-use.In this period also, in the United States, precast prestressed roof beams and floor beams were used in many school buildings, occasionally 32 m long or more. Such long beams over a single span could not possibly be successful in reinforced concrete unless they were cast on site because they would have to be much deeper and much heavier than prestressed concrete beams. They would certainlly be less pleasing to the eye and often more expensive than the prestressed concrete beams. These school buildings have a strong, simple architectural appeal and will be a pleasure to look at for many years.The most important parts of a precast prestressed concrete beam are the tendons and the concrete. The tendons, as the name implies, are the cables, rods or wires of steel which are under tension in the concrete.Before the concrete has hardened (before transfer of stress), the tendons are either unstressed (post-tensioned prestressing) or are stressed and held by abutments outside the concrete ( pre-tensioned prestressing). While the concrete is hardening it grips each tendon more and more tightly by bond along its full length. End anchorages consisting of plates or blocks are placed on the ends of the tendons of post-tensioned prestressed units, and such tendons are stressed up at the time of transfer, when the concrete has hardened sufficiently. In the other type of pretressing, with pre-tensioned tendons, the tendons are released from external abutments at the moment of transfer, and act on the concrete through bond or archorage or both, shortening it by compression, and themselves also shortening and losing some tension.Further shortening of the concrete (and therefore of the steel) takes place with time. The concrete is said to creep. This means that it shortens permanently under load and spreads the stresses more uniformly and thus more safely across its section. Steel also creeps, but rather less. The result of these two effects ( and of the concrete shrinking when it dries ) is that prestressed concrete beams are never more highly stressed than at the moment of transfer.The factory precasting of long prestressed concrete beams is likely to become more and more popular in the future, but one difficulty will be road transport. As the length of the beam increases, the lorry becomes less and less manoeuvrable until eventually the only suitable time for it to travel is in the middle of the night when traffic in the district and the route, whether the roads are straight or curved. Precasting at the site avoids these difficulties; it may be expensive, but it has often been used for large bridge beams.混凝土工艺及发展波特兰水泥混凝土在当今世界已成为建造数量繁多、种类复杂结构的首选材料。
钢筋混凝土结构中英文对照外文翻译文献
中英文对照外文翻译(文档含英文原文和中文翻译)Reinforced ConcreteConcrete and reinforced concrete are used as building materials in every country. In many, including the United States and Canada, reinforced concrete is a dominant structural material in engineered construction. The universal nature of reinforced concrete construction stems from the wide availability of reinforcing bars and the constituents of concrete, gravel, sand, and cement, the relatively simple skills required in concrete construction, and the economy of reinforced concrete compared to other forms of construction. Concrete and reinforced concrete are used in bridges, buildings of all sorts underground structures, water tanks, television towers, offshore oil exploration and production structures, dams, and even in ships.Reinforced concrete structures may be cast-in-place concrete, constructed in their final location, or they may be precast concreteproduced in a factory and erected at the construction site. Concrete structures may be severe and functional in design, or the shape and layout and be whimsical and artistic. Few other building materials off the architect and engineer such versatility and scope.Concrete is strong in compression but weak in tension. As a result, cracks develop whenever loads, or restrained shrinkage of temperature changes, give rise to tensile stresses in excess of the tensile strength of the concrete. In a plain concrete beam, the moments about the neutral axis due to applied loads are resisted by an internal tension-compression couple involving tension in the concrete. Such a beam fails very suddenly and completely when the first crack forms. In a reinforced concrete beam, steel bars are embedded in the concrete in such a way that the tension forces needed for moment equilibrium after the concrete cracks can be developed in the bars.The construction of a reinforced concrete member involves building a from of mold in the shape of the member being built. The form must be strong enough to support both the weight and hydrostatic pressure of the wet concrete, and any forces applied to it by workers, concrete buggies, wind, and so on. The reinforcement is placed in this form and held in place during the concreting operation. After the concrete has hardened, the forms are removed. As the forms are removed, props of shores are installed to support the weight of the concrete until it has reached sufficient strength to support the loads by itself.The designer must proportion a concrete member for adequate strength to resist the loads and adequate stiffness to prevent excessive deflections. In beam must be proportioned so that it can be constructed. For example, the reinforcement must be detailed so that it can be assembled in the field, and since the concrete is placed in the form after the reinforcement is in place, the concrete must be able to flow around, between, and past the reinforcement to fill all parts of the form completely.The choice of whether a structure should be built of concrete, steel, masonry, or timber depends on the availability of materials and on a number of value decisions. The choice of structural system is made by the architect of engineer early in the design, based on the following considerations:1. Economy. Frequently, the foremost consideration is the overall const of the structure. This is, of course, a function of the costs of the materials and the labor necessary to erect them. Frequently, however, the overall cost is affected as much or more by the overall construction time since the contractor and owner must borrow or otherwise allocate money to carry out the construction and will not receive a return on this investment until the building is ready for occupancy. In a typical large apartment of commercial project, the cost of construction financing will be a significant fraction of the total cost. As a result, financial savings due to rapid construction may more than offset increased material costs. For this reason, any measures the designer can take to standardize the design and forming will generally pay off in reduced overall costs.In many cases the long-term economy of the structure may be more important than the first cost. As a result, maintenance and durability are important consideration.2. Suitability of material for architectural and structural function.A reinforced concrete system frequently allows the designer to combine the architectural and structural functions. Concrete has the advantage that it is placed in a plastic condition and is given the desired shape and texture by means of the forms and the finishing techniques. This allows such elements ad flat plates or other types of slabs to serve as load-bearing elements while providing the finished floor and / or ceiling surfaces. Similarly, reinforced concrete walls can provide architecturally attractive surfaces in addition to having the ability to resist gravity, wind, or seismic loads. Finally, the choice of size of shape is governed by the designer and not by the availability of standard manufactured members.3. Fire resistance. The structure in a building must withstand the effects of a fire and remain standing while the building is evacuated and the fire is extinguished. A concrete building inherently has a 1- to 3-hour fire rating without special fireproofing or other details. Structural steel or timber buildings must be fireproofed to attain similar fire ratings.4. Low maintenance.Concrete members inherently require less maintenance than do structural steel or timber members. This is particularly true if dense, air-entrained concrete has been used forsurfaces exposed to the atmosphere, and if care has been taken in the design to provide adequate drainage off and away from the structure. Special precautions must be taken for concrete exposed to salts such as deicing chemicals.5. Availability of materials. Sand, gravel, cement, and concrete mixing facilities are very widely available, and reinforcing steel can be transported to most job sites more easily than can structural steel. As a result, reinforced concrete is frequently used in remote areas.On the other hand, there are a number of factors that may cause one to select a material other than reinforced concrete. These include:1. Low tensile strength.The tensile strength concrete is much lower than its compressive strength ( about 1/10 ), and hence concrete is subject to cracking. In structural uses this is overcome by using reinforcement to carry tensile forces and limit crack widths to within acceptable values. Unless care is taken in design and construction, however, these cracks may be unsightly or may allow penetration of water. When this occurs, water or chemicals such as road deicing salts may cause deterioration or staining of the concrete. Special design details are required in such cases. In the case of water-retaining structures, special details and / of prestressing are required to prevent leakage.2. Forms and shoring. The construction of a cast-in-place structure involves three steps not encountered in the construction of steel or timber structures. These are ( a ) the construction of the forms, ( b ) the removal of these forms, and (c) propping or shoring the new concrete to support its weight until its strength is adequate. Each of these steps involves labor and / or materials, which are not necessary with other forms of construction.3. Relatively low strength per unit of weight for volume.The compressive strength of concrete is roughly 5 to 10% that of steel, while its unit density is roughly 30% that of steel. As a result, a concrete structure requires a larger volume and a greater weight of material than does a comparable steel structure. As a result, long-span structures are often built from steel.4. Time-dependent volume changes. Both concrete and steel undergo-approximately the same amount of thermal expansion and contraction. Because there is less mass of steel to be heated or cooled,and because steel is a better concrete, a steel structure is generally affected by temperature changes to a greater extent than is a concrete structure. On the other hand, concrete undergoes frying shrinkage, which, if restrained, may cause deflections or cracking. Furthermore, deflections will tend to increase with time, possibly doubling, due to creep of the concrete under sustained loads.In almost every branch of civil engineering and architecture extensive use is made of reinforced concrete for structures and foundations. Engineers and architects requires basic knowledge of reinforced concrete design throughout their professional careers. Much of this text is directly concerned with the behavior and proportioning of components that make up typical reinforced concrete structures-beams, columns, and slabs. Once the behavior of these individual elements is understood, the designer will have the background to analyze and design a wide range of complex structures, such as foundations, buildings, and bridges, composed of these elements.Since reinforced concrete is a no homogeneous material that creeps, shrinks, and cracks, its stresses cannot be accurately predicted by the traditional equations derived in a course in strength of materials for homogeneous elastic materials. Much of reinforced concrete design in therefore empirical, i.e., design equations and design methods are based on experimental and time-proved results instead of being derived exclusively from theoretical formulations.A thorough understanding of the behavior of reinforced concrete will allow the designer to convert an otherwise brittle material into tough ductile structural elements and thereby take advantage of concrete’s desirable characteristics, its high compressive strength, its fire resistance, and its durability.Concrete, a stone like material, is made by mixing cement, water, fine aggregate ( often sand ), coarse aggregate, and frequently other additives ( that modify properties ) into a workable mixture. In its unhardened or plastic state, concrete can be placed in forms to produce a large variety of structural elements. Although the hardened concrete by itself, i.e., without any reinforcement, is strong in compression, it lacks tensile strength and therefore cracks easily. Because unreinforced concrete is brittle, it cannot undergo large deformations under load and failssuddenly-without warning. The addition fo steel reinforcement to the concrete reduces the negative effects of its two principal inherent weaknesses, its susceptibility to cracking and its brittleness. When the reinforcement is strongly bonded to the concrete, a strong, stiff, and ductile construction material is produced. This material, called reinforced concrete, is used extensively to construct foundations, structural frames, storage takes, shell roofs, highways, walls, dams, canals, and innumerable other structures and building products. Two other characteristics of concrete that are present even when concrete is reinforced are shrinkage and creep, but the negative effects of these properties can be mitigated by careful design.A code is a set technical specifications and standards that control important details of design and construction. The purpose of codes it produce structures so that the public will be protected from poor of inadequate and construction.Two types f coeds exist. One type, called a structural code, is originated and controlled by specialists who are concerned with the proper use of a specific material or who are involved with the safe design of a particular class of structures.The second type of code, called a building code, is established to cover construction in a given region, often a city or a state. The objective of a building code is also to protect the public by accounting for the influence of the local environmental conditions on construction. For example, local authorities may specify additional provisions to account for such regional conditions as earthquake, heavy snow, or tornados. National structural codes genrally are incorporated into local building codes.The American Concrete Institute ( ACI ) Building Code covering the design of reinforced concrete buildings. It contains provisions covering all aspects of reinforced concrete manufacture, design, and construction. It includes specifications on quality of materials, details on mixing and placing concrete, design assumptions for the analysis of continuous structures, and equations for proportioning members for design forces.All structures must be proportioned so they will not fail or deform excessively under any possible condition of service. Therefore it is important that an engineer use great care in anticipating all the probableloads to which a structure will be subjected during its lifetime.Although the design of most members is controlled typically by dead and live load acting simultaneously, consideration must also be given to the forces produced by wind, impact, shrinkage, temperature change, creep and support settlements, earthquake, and so forth.The load associated with the weight of the structure itself and its permanent components is called the dead load. The dead load of concrete members, which is substantial, should never be neglected in design computations. The exact magnitude of the dead load is not known accurately until members have been sized. Since some figure for the dead load must be used in computations to size the members, its magnitude must be estimated at first. After a structure has been analyzed, the members sized, and architectural details completed, the dead load can be computed more accurately. If the computed dead load is approximately equal to the initial estimate of its value ( or slightly less ), the design is complete, but if a significant difference exists between the computed and estimated values of dead weight, the computations should be revised using an improved value of dead load. An accurate estimate of dead load is particularly important when spans are long, say over 75 ft ( 22.9 m ), because dead load constitutes a major portion of the design load.Live loads associated with building use are specific items of equipment and occupants in a certain area of a building, building codes specify values of uniform live for which members are to be designed.After the structure has been sized for vertical load, it is checked for wind in combination with dead and live load as specified in the code. Wind loads do not usually control the size of members in building less than 16 to 18 stories, but for tall buildings wind loads become significant and cause large forces to develop in the structures. Under these conditions economy can be achieved only by selecting a structural system that is able to transfer horizontal loads into the ground efficiently.钢筋混凝土在每一个国家，混凝土及钢筋混凝土都被用来作为建筑材料。
土木工程专业钢筋混凝土结构设计毕业论文外文文献翻译及原文
毕业设计（论文）外文文献翻译文献、资料中文题目：钢筋混凝土结构设计文献、资料英文题目：DESIGN OF REINFORCED CONCRETE STRUCTURES 文献、资料来源：文献、资料发表（出版）日期：院（部）：专业：土木工程班级：姓名：学号：指导教师：翻译日期： 2017.02.14毕业设计（论文）外文参考资料及译文译文题目：DESIGN OF REINFORCED CONCRETE STRUCTURES原文：DESIGN OF REINFORCED CONCRETESTRUCTURES1. BASIC CONCERPTS AND CHARACERACTERISTICS OF REINFORCED CONCRETEPlain concrete is formed from hardened mixture of cement, water , fine aggregate , coarse aggregate (crushed stone or gravel ) , air and often other admixtures . The plastic mix is placed and consolidated in the formwork, then cured to accelerate of the chemical hydration of hen cement mix and results in a hardened concrete. It is generally known that concrete has high compressive strength and low resistance to tension. Its tensile strength is approximatelyone-tenth of its compressive strength. Consequently, tensile reinforcement in the tension zone has to be provided to supplement the tensile strength of the reinforced concrete section.For example, a plain concrete beam under a uniformly distributed load q is shown in Fig .1.1(a), when the distributed load increases and reaches a value q=1.37KN/m , the tensile region at the mid-span will be cracked and the beam will fail suddenly . A reinforced concrete beam if the same size but has to steel reinforcing bars (2φ16) embedded at the bottom under a uniformly distributed load q is shown in Fig.1.1(b). The reinforcing bars take up the tension there after the concrete is cracked. When the load q is increased, the width of the cracks, the deflection and thestress of steel bars will increase . When the steel approaches the yielding stress ƒy , thedeflection and the cracked width are so large offering some warning that the compression zone . The failure load q=9.31KN/m, is approximately 6.8 times that for the plain concrete beam.Concrete and reinforcement can work together because there is a sufficiently strong bond between the two materials, there are no relative movements of the bars and the surrounding concrete cracking. The thermal expansion coefficients of the two materials are 1.2×10-5K-1 for steel and 1.0×10-5~1.5×10-5K-1 for concrete .Generally speaking, reinforced structure possess following features :Durability .With the reinforcing steel protected by the concrete , reinforced concreteFig.1.1Plain concrete beam and reinforced concrete beamIs perhaps one of the most durable materials for construction .It does not rot rust , and is not vulnerable to efflorescence .(2)Fire resistance .Both concrete an steel are not inflammable materials .They would not be affected by fire below the temperature of 200℃when there is a moderate amount of concrete cover giving sufficient thermal insulation to the embedded reinforcement bars.(3)High stiffness .Most reinforced concrete structures have comparatively large cross sections .As concrete has high modulus of elasticity, reinforced concrete structures are usuallystiffer than structures of other materials, thus they are less prone to large deformations, This property also makes the reinforced concrete less adaptable to situations requiring certainflexibility, such as high-rise buildings under seismic load, and particular provisions have to be made if reinforced concrete is used.(b)Reinfoced concrete beam(4)Locally available resources. It is always possible to make use of the local resources of labour and materials such as fine and coarse aggregates. Only cement and reinforcement need to be brought in from outside provinces.(5)Cost effective. Comparing with steel structures, reinforced concrete structures are cheaper.(6)Large dead mass, The density of reinforced concrete may reach2400~2500kg/pare with structures of other materials, reinforced concrete structures generally have a heavy dead mass. However, this may be not always disadvantageous, particularly for those structures which rely on heavy dead weight to maintain stability, such as gravity dam and other retaining structure. The development and use of light weight aggregate have to a certain extent make concrete structure lighter.(7)Long curing period.. It normally takes a curing period of 28 day under specified conditions for concrete to acquire its full nominal strength. This makes the progress of reinforced concrete structure construction subject to seasonal climate. The development of factory prefabricated members and investment in metal formwork also reduce the consumption of timber formwork materials.(8)Easily cracked. Concrete is weak in tension and is easily cracked in the tension zone. Reinforcing bars are provided not to prevent the concrete from cracking but to take up the tensile force. So most of the reinforced concrete structure in service is behaving in a cracked state. This is an inherent is subjected to a compressive force before working load is applied. Thus the compressed concrete can take up some tension from the load.2. HISTOEICAL DEVELPPMENT OF CONCRETE STRUCTUREAlthough concrete and its cementitious(volcanic) constituents, such as pozzolanic ash, have been used since the days of Greek, the Romans, and possibly earlier ancient civilization, the use of reinforced concrete for construction purpose is a relatively recent event, In 1801, F. Concrete published his statement of principles of construction, recognizing the weakness if concrete in tension, The beginning of reinforced concrete is generally attributed to Frenchman J. L. Lambot, who in 1850 constructed, for the first time, a small boat with concrete for exhibition in the 1855 World’s Fair in Paris. In England, W. B. Wilkinson registered a patent for reinforced concrete l=floor slab in 1854.J.Monier, a French gardener used metal frames as reinforcement to make garden plant containers in 1867. Before 1870, Monier had taken a series of patents to make reinforcedconcrete pipes, slabs, and arches. But Monier had no knowledge of the working principle of this new material, he placed the reinforcement at the mid-depth of his wares. Then little construction was done in reinforced concrete. It is until 1887, when the German engineers Wayss and Bauschinger proposed to place the reinforcement in the tension zone, the use of reinforced concrete as a material of construction began to spread rapidly. In1906, C. A. P. Turner developed the first flat slab without beams.Before the early twenties of 20th century, reinforced concrete went through the initial stage of its development, Considerable progress occurred in the field such that by 1910 the German Committee for Reinforced Concrete, the Austrian Concrete Committee, the American Concrete Institute, and the British Concrete Institute were established. Various structural elements, such as beams, slabs, columns, frames, arches, footings, etc. were developed using this material. However, the strength of concrete and that of reinforcing bars were still very low. The common strength of concrete at the beginning of 20th century was about 15MPa in compression, and the tensile strength of steel bars was about 200MPa. The elements were designed along the allowable stresses which was an extension of the principles in strength of materials.By the late twenties, reinforced concrete entered a new stage of development. Many buildings, bridges, liquid containers, thin shells and prefabricated members of reinforced concrete were concrete were constructed by 1920. The era of linear and circular prestressing began.. Reinforced concrete, because of its low cost and easy availability, has become the staple material of construction all over the world. Up to now, the quality of concrete has been greatly improved and the range of its utility has been expanded. The design approach has also been innovative to giving the new role for reinforced concrete is to play in the world of construction.The concrete commonly used today has a compressive strength of 20~40MPa. For concrete used in pre-stressed concrete the compressive strength may be as high as 60~80MPa. The reinforcing bars commonly used today has a tensile strength of 400MPa, and the ultimate tensile strength of prestressing wire may reach 1570~1860Pa. The development of high strength concrete makes it possible for reinforced concrete to be used in high-rise buildings, off-shore structures, pressure vessels, etc. In order to reduce the dead weight of concrete structures, various kinds of light concrete have been developed with a density of 1400~1800kg/m3. With a compressive strength of 50MPa, light weight concrete may be used in load bearing structures. One of the best examples is the gymnasium of the University of Illinois which has a span of 122m and is constructed of concrete with a density of 1700kg/m3. Another example is the two 20-story apartment houses at the Xi-Bian-Men in Beijing. The walls of these two buildings are light weight concrete with a density of 1800kg/m3.The tallest reinforced concrete building in the world today is the 76-story Water Tower Building in Chicago with a height of 262m. The tallest reinforced concrete building in China today is the 63-story International Trade Center in GuangZhou with a height a height of 200m. The tallest reinforced concrete construction in the world is the 549m high International Television Tower in Toronto, Canada. He prestressed concrete T-section simply supported beam bridge over the Yellow River in Luoyang has 67 spans and the standard span length is 50m.In the design of reinforced concrete structures, limit state design concept has replaced the old allowable stresses principle. Reliability analysis based on the probability theory has very recently been introduced putting the limit state design on a sound theoretical foundation. Elastic-plastic analysis of continuous beams is established and is accepted in most of the design codes. Finite element analysis is extensively used in the design of reinforced concrete structures and non-linear behavior of concrete is taken into consideration. Recent earthquake disasters prompted the research in the seismic resistant reinforced of concrete structures. Significant results have been accumulated.3. SPECIAL FEATURES OF THE COURSEReinforced concrete is a widely used material for construction. Hence, graduates of every civil engineering program must have, as a minimum requirement, a basic understanding of the fundamentals of reinforced concrete.The course of Reinforced Concrete Design requires the prerequisite of Engineering Mechanics, Strength of Materials, and some if not all, of Theory of Structures, In all these courses, with the exception of Strength of Materials to some extent, a structure is treated of in the abstract. For instance, in the theory of rigid frame analysis, all members have an abstract EI/l value, regardless of what the act value may be. But the theory of reinforced concrete is different, it deals with specific materials, concrete and steel. The values of most parameters must be determined by experiments and can no more be regarded as some abstract. Additionally, due to the low tensile strength of concrete, the reinforced concrete members usually work with cracks, some of the parameters such as the elastic modulus I of concrete and the inertia I of section are variable with the loads.The theory of reinforced concrete is relatively young. Although great progress has been made, the theory is still empirical in nature in stead of rational. Many formulas can not be derived from a few propositions, and may cause some difficulties for students. Besides, due to the difference in practice in different countries, most countries base their design methods on their own experience and experimental results. Consequently, what one learns in one country may be different in another country. Besides, the theory is still in a stage of rapid。
土木工程专业Reinforced-Concrete钢筋混凝土大学毕业论文外文文献翻译及原文
毕业设计（论文）外文文献翻译文献、资料中文题目：钢筋混凝土文献、资料英文题目：Reinforced Concrete文献、资料来源： __________________________ 文献、资料发表（出版）日期： _____________________ 院（部）:专业：_________________________________________ 班级：_________________________________________ 姓名：_________________________________________ 学号：_________________________________________ 指导教师：翻译日期：2017.02.14外文文献翻译Reinforced ConcreteCon crete and rein forced con crete are used as build ing materials in every coun try. In many, in clud ing the Un ited States and Can ada, rein forced con crete is a dominant structural material in engin eered con structi on.The uni versal n ature of rein forced con crete con structi on stems from the wide availability of rei nforci ng bars and the con stitue nts of con crete, gravel, sand, and cement, the relatively simple skills required in con crete con structi on, and the economy of rein forced con crete compared to other forms of con structi on. Con crete and rein forced con crete are used in bridges, build ings of all sorts un dergro und structures, water tan ks, televisi on towers, offshore oil explorati on and product ion structures, dams, and eve n in ships.Rein forced con crete structures may be cast-i n-place con crete, con structed in their fin al locatio n, or they may be precast con crete produced in a factory and erected at the con structi on site. Con crete structures maybe severe and functional in design, or the shape and layout and be whimsical and artistic. Few other buildi ng materials off the architect and engin eer such versatility and scope.Con crete is stro ng in compressi on but weak in tension. As a result, cracks develop whe never loads, or restrai ned shri nkage of temperature changes, give rise to tensile stresses in excess of the tensile strengthof the con crete. In a pla in con crete beam, the mome nts about the n eutral axis due to applied loads are resisted by an internal tension-compression couple involving tension in the concrete. Such a beamfails very suddenly and completely when the first crack forms. In a reinforced concrete beam, steel bars are embedded in the con crete in such a way that the tension forces n eeded for mome nt equilibrium after the con crete cracks can be developed in the bars.The con structi on of a rein forced con crete member invo Ives build ing a from of mold in the shape of the member being built. The form must be strong eno ugh to support both the weight and hydrostatic pressure of the wet concrete, and any forces applied to it by workers, concrete buggies,wind, and so on. The reinforcement is placed in this form and held in place duri ng the con cret ing operati on. After the con crete has harde ned, the forms are removed. As the forms are removed, props of shores are in stalled to support the weight of the con crete un til it has reached sufficie nt stre ngth to support the loadsby itself.The designer must proportion a concrete memberfor adequate strengthto resist the loads and adequate stiffness to prevent excessive deflecti ons. In beam must be proporti oned sothat it can be con structed.For example, the reinforcement must be detailed so that it can beassembled in the field, and since the con crete is placed in the form after the rei nforceme nt is inplace, the con crete must be ableto flow around,between, andpast the reinforcement to fill all parts of the form completely.The choice of whether a structure should be built of concrete, steel, masonry, or timber depends on the availability of materials and on a number of value decisions.The choice of structural system is made by thearchitect of engineer early in the design, based on the followingcon siderati ons:1. Economy. Freque ntly, the foremost con sideratio n is the overall const of the structure. This is, of course, a fun cti on of the costs ofthe materials and the labor necessary to erect them. Frequently, however, the overall cost is affected as much or more by the overall con structi on time since the con tractor and owner must borrow or otherwise allocate money to carry out the con struct ion and will not receive a retur n on this investment until the building is ready for occupancy. In a typical large apartme nt of commercial project, the cost of con struct ion financing willbe a significant fraction of the total cost. As a result, financial savings due to rapid con structi on may more tha n offset in creased material costs. For this reas on, any measures the desig ner can take to sta ndardize the desig n and forming will gen erally pay off in reduced overall costs.In many cases the Ion g-term economy of the structure may be more importa nt tha n the first cost. As a result, maintenance and durability are importa nt con siderati on.2. Suitability of material for architectural and structural function.A rein forced con crete system freque ntly allows the desig ner to comb ine the architectural and structural functions. Con crete has the adva ntage that it is placed in a plastic con diti on and is give n the desired shapeand texture by meansof the forms and the finishing techniques. This allows such elements ad flat plates or other types of slabs to serve as load-bearingelements while providing the finished floor and / or ceiling surfaces. Similarly, rein forced con crete walls can providearchitecturally attractive surfaces in addition to having the ability to resist gravity, wind, or seismic loads. Fin ally, the choice of size of shape is governed by the designer and not by the availability of standard manu factured members.3. Fire resista nee. The structure in a buildi ng must withsta nd theeffects of a fire and rema in sta nding while the build ing is evacuated and the fire is exti nguished. A con crete buildi ng in here ntly has a 1- to 3-hour fire rat ing without special fireproofi ng or other details. Structural steel or timber build ings must be fireproofed to atta in similar fire ratin gs.4. Low maintenan ce. Con crete members in here ntly require less maintenance than do structural steel or timber members. This is particularly true if den se, air-e ntrained con crete has bee n used forsurfaces exposed to the atmosphere, and if care has bee n take n in the desig n to provide adequate drain age off and away from the structure. Special precauti ons must be take n for con crete exposed to salts such as deici ng chemicals.5. Availability of materials. Sand, gravel, ceme nt, and con cretemixi ng facilities are very widely available, and rein forci ng steel canbe tran sported to most job sites more easily tha n can structural steel. As a result, re in forced con crete is freque ntly used in remote areas.On the other hand, there are a nu mber of factors that may cause one to selecta material other tha n rein forced con crete. These in clude:1. Low tensile strength. The tensile strength concrete is much lower than its compressive strength ( about 1/10 ), and hence concrete is subject to crack ing. In structural uses this is overcome by using rei nforceme nt to carry ten sile forces and limit crack widths to with in acceptable values. Un less care is take n in desig n and con struct ion, however, these cracks maybe unsightly or mayallow penetration of water. Wherthis occurs, water or chemicals such as road deicing salts may cause deterioration or stai ning of the con crete. Special desig n details are required in such cases. In the case of water-retai ning structures, special details and /of prestress ing are required to preve nt leakage.2. Forms and shori ng. The con structi on of a cast-i n-place structureinvo Ives three steps not encoun tered in the con struct ion of steel or timberstructures. These are ( a ) the con struct ion of the forms, ( b ) the removal of these forms, and (c) propp ing or shori ng the new con crete to support its weight until itsstrength is adequate. Each of these steps invoIves labor and / or materials, which are not necessary with other forms of con structi on.3. Relatively low strength per unit of weight for volume. Thecompressive strength of concrete is roughly 5 to 10%that of steel, while its unit den sity is roughly 30% that of steel. As a result, a con cretestructure requires a larger volume and a greater weight of material than does acomparable steel structure. As a result, Iong-span structures are ofte n built from steel.4. Time-depe ndent volume cha nges. Both con crete and steelundergo-approximately the same amount of thermal expansionandcon tracti on. Because there is less mass of steel to be heated or cooled, andbecause steel is a better con crete, a steel structure is gen erallyaffected by temperature cha nges to a greater exte nt tha n is a con crete structure.On the other hand, con crete un dergoes fryi ng shri nkage, which, if restrained, may cause deflections or cracking. Furthermore, deflecti ons will tend to in crease with time, possibly doubli ng, due to creep of the con crete un der susta ined loads.In almost every branch of civil extensiveuse is made of reinforced foundations.Engineers and architects reinforced con crete desig n throughout theirprofessi onal careers. Muchof this text is directly concerned with the behavior and proporti oningof components that makeup typical reinforced concrete structures-beams, colu mns, and slabs. Once the behavior of these in dividual eleme nts is un derstood, the desig ner will have the backgro und to an alyze and desig n a wide range of complex structures, such as foun datio ns, buildi ngs, and bridges, composed of these eleme nts.Si nee rei nforced concrete is a no homogeneous material that creeps, shri nks,and cracks, its stresses cannot be accurately predicted by the traditi onal equati ons derived in a course in stre ngth of materials forhomoge neous elastic materials. Much of rein forced con crete desig n in thereforeempirical, i.e., design equations and design methods are based on experime ntal and engineering and architecture con crete for structures and requires basic knowledge oftime-proved results in stead of being derived exclusively from theoretical formulati ons.A thorough un dersta nding of the behavior of rein forced con crete will allow the desig ner to con vert an otherwise brittle material into tough ductile structural elements and thereby take advantage of concrete ' s desirable characteristics, its high compressive stre ngth, its fire resista nee, and its durability.Concrete, a stone like material, is madeby mixing cement, water, fine aggregate ( often sand ), coarse aggregate, and frequently other additives (that modify properties ) into a workable mixture. In its un harde ned or plastic state, concrete can be placed in forms to produce a large variety of structural eleme nts. Although the harde ned con crete by itself, i.e., without any rein forceme nt, is stro ng in compressi on, it lacks ten sile stre ngth and therefore cracks easily. Because unrein forced con crete is brittle, it cannot undergo large deformations under load and fails sudde nly-without warni ng. The additi on fo steel rein forceme nt to the con crete reduces the n egative effects of its two prin cipal in here nt weaknesses, its susceptibility to cracking and its brittleness. Whenthe rein forceme nt is stro ngly bon ded to the con crete, a strong, stiff, and ductile con struct ion material is produced. This material, calledrei nforced con crete, is used exte nsively to con struct foun dati ons,structural frames, storage takes, shell roofs, highways, walls, dams, canals, and innumerable other structures and building products. Twoother characteristics of concrete that are present even when concrete is rein forced are shri nkage and creep, but the n egative effects of these properties can be mitigated by careful desig n.A code is a set tech ni cal specificati ons and sta ndards that con trol importa nt details of desig n and con struct ion. The purpose of codes it produce structures so that the public will be protected from poor of in adequate and con struct ion.Two types f coeds exist. One type, called a structural code, is orig in ated and con trolled by specialists whoare concerned with the proper use of a specific material or who are invo Ived with the safe desig n of a particular class of structures.The sec ond type of code, called a build ing code, is established to cover con struct ion in a give n region, ofte n a city or a state. The objective of a build ing code is also to protect the public by acco un ti ng for the in flue nee of the local en vir onmen tal con diti ons on con structi on. For example, local authorities may specifyadditional provisions toaccount for such regional conditions as earthquake, heavy snow, ortorn ados. Nati onal structural codes gen rally are in corporated into local build ing codes.The America n Con crete In stitute ( ACI ) Buildi ng Code coveri ng the desig n of rein forced con crete build in gs. It contains provisi ons coveri ngall aspects of re in forced con crete manu facture, desig n, and con structi on. It includes specifications on quality of materials, details on mixing andplacing concrete, design assumptions for the analysis of continuous structures, and equati ons for proporti oning members for desig n forces.All structures must be proporti oned so they will not fail or deform excessively un der any possible con diti on of service. Therefore it is important that an engineer use great care in anticipating all the probable loads to which a structure will be subjected duri ng its lifetime.Although the desig n of most members is con trolled typically by dead and live load acting simultaneously, consideration must also be given tothe forces produced by wind, impact, shrinkage, temperature change, creep and support settleme nts, earthquake, and so forth.The load associated with the weight of the structure itself and its perma nent comp onents is called the dead load. The dead load of con crete members, which is substantial, should never be neglected in design computations. The exact magnitude of the dead load is not known accurately un til members have bee n sized. Since some figure for the dead load must be used in computations to size the members, its magnitude must be estimated at first. After a structure has been analyzed, the memberssized, and architectural details completed, the dead load can be computed more accurately. If the computed dead load is approximately equal to the initial estimate of its value ( or slightly less ), the design is complete,but if a significant differenee exists between the computed and estimated values of dead weight, the computations should be revised using an improved value of dead load. An accurate estimate of dead load is particularly importa nt whe n spa ns are long, say over 75 ft ( 22.9 m ),because dead load con stitutes a major porti on of the desig n load.Live loads associated with building use are specific items of equipme nt and occupa nts in a certa in area of a build ing, buildi ng codes specify values of un iform live for which members are to be desig ned.After the structure has bee n sized for vertical load, it is checkedfor wi nd in comb in ati on with dead and live load as specified in the code. Windloads do not usually con trol the size of members in buildi ng lessthan 16 to 18 stories, but for tall buildings wind loads becomesignificant and cause large forces to develop in the structures. Under these conditions economycan be achieved only by selecting a structural system that is able to tran sfer horiz on tal loads into the ground efficie ntly.钢筋混凝土在每一个国家，混凝土及钢筋混凝土都被用来作为建筑材料。
土木工程混凝土论文中英文资料外文翻译文献
土木工程混凝土论文中英文资料外文翻译文献外文资料STUDIES ON IMPACT STRENGTH OF CONCRETESUBJECTED TO SUSTAINEDELEVATED TEMPERATUREConcrete has a remarkable fire resisting properties. Damage in concrete due to fire depends on a great extent on the intensity and duration of fire. Spalling cracking during heating are common concrete behaviour observed in the investigation of the fire affected structures. Plenty of literature is available on the studies of concrete based on time temperature cures. In power, oil sectorsand nuclear reactors concrete is exposed to high temperature for considerable period of time. These effects can be reckoned as exposure to sustained elevated temperature. The sustained elevated temperature may be varying from a few hours to a number of years depending upon practical condition of exposures. The knowledge on properties under such conditions is also of prime importance apart from the structures subjected to high intensity fire. Impact studies of structure subjected to sustained elevated temperature becomes more important as it involves sensitive structures which is more prone to attacks and accidents. In this paper impact studies on concrete subjected to sustained elevated temperature has been discussed. Experiments have been conducted on 180 specimens along with 180 companion cube specimens. The temperatures of 100°C, 200°C and 300°C for a duration of exposure of 2 hours 4 hours and 6 hours has been considered in the experiments. The results are logically analyzed and concluded.1. INTRODUCTIONThe remarkable property of concrete to resist the fire reduces the damage in a concrete structure whenever there is an accidental fire. In most of the cases the concrete remains intact with minor damages only. The reason being low thermal conductivity of concrete at higher temperatures and hence limiting the depth of penetration of firedamage. But when the concrete is subjected to high temperature for long duration the deterioration of concrete takes place. Hence it is essential to understand the strength and deformation characteristics of concrete subjected to temperature for long duration. In this paper an attempt has been made to study the variation in Impact Strength of concrete when subjected to a temperature range 100oC, 200oC and 300oC sustained for a period of 2 hrs, 4 hrs and 6 hrs.The review of the literature shows that a lot of research work [1 – 3] has taken place on the effect of elevated temperature on concrete. All these studies are based on time –temperature curves. Hence an attempt has been made to study the effect of sustained elevated temperature on impact strength of concrete and the results are compared with the compressive strength. The experimental programme has been planned for unstressed residual strength test based on the available facilities. Residual strength is the strength of heated and subsequently cooled concrete specimens expressed as percentage of the strength of unheated specimens.2. EXPERIMENTAL INVESTIGATION2.1. TEST SPECIMEN AND MATERIALSA total of 180 specimens were tested in the present study along with 180 companion cubes. An electric oven capable of reaching a maximum temperature of 300oC has been used for investigation. Fine and coarse aggregates conforming to IS383 has been used to prepare the specimen with mix proportions M1 = 1:2.1:3.95 w/c = 0.58, M2 = 1:1.15:3.56 w/c = 0.53, M3 = 1:0.8:2.4 w/c = 0.4.2.2 TEST VARIABLESThe effects of the following variables were studied.2.2.1 Size sSize of Impact Strength Test Specimen was 150 mm dial and 64 mm thickness and size of companion cube 150 x 150 x 150 mm.2.2.2 Maximum TemperatureIn addition to room temperature, the effect of three different temperatures (100oC, 200oC and 300oC) on the compressive strength was investigated.2.2.3 Exposure Time at Maximum TemperatureThree different exposure times were used to investigate the influence of heat on compressive strength; they are 2 hrs, 4 hrs and 6 hrs.2.2.4 Cooling MethodSpecimens were cooled in air to room temperature.3. TEST PROCEDUREAll the specimens were cast in steel moulds as per IS516 and each layer was compacted. Specimens were then kept in their moulds for 24 hours after which they were decoupled and placed into a curing tank until 28 days. After which the specimens were removed and were allowed to dry in room temperature. These specimens were kept in the oven and the required target temperature was set. Depending on the number of specimen kept inside the oven the time taken to reach the steady state was found to vary. After the steady state was reached the specimens were subjected to predetermined steady duration at the end of which the specimens are cooled to room temperature and tested.ACI drop weight impact strength test was adopted. This is the simplest method for evaluating impact resistance of concrete. The size of the specimen is 150 mm dial and 64 mm thickness. The disc specimens were prepared using steel moulds cured and heated and cooled as. This consists of a standard manually operated 4.54 kg hammer with 457 mm drop. A 64 mm hardened steel ball and a flat base plate with positioning bracket and lugs. The specimen is placed between the four guides pieces (lugs) located 4.8 mm away from the sample. A frame (positioning bracket) is then built in order to target the steel ball at the centre of concrete disc. The disc is coated at the bottom with a thin layer of petroleum jelly or heavy grease to reduce the friction between the specimen and base plate. The bottom part of the hammer unit was placed with its base upon the steel ball and the load was applied by dropping weight repeatedly. The loading was continued until the disc failed and opened up such that it touched three of the four positioning lugs. The number of blows that caused this condition is recorded as the failure strength. The companion cubes were tested for cube compression strength (fake).4. ANALYSIS AND RESULTS4.1 RESIDUAL COMPRESSIVE STRENGTH VS. TEMPERATUREFrom Table 1, at 100°C sustained elevated temperature it is seen that the residual strength of air cooled specimens of mixes M1, M2 and M3 has increased in strength 114% for M1 mix, 109% for M2 mix and 111% for M3 mix for 6 hours duration of exposure. When the sustained elevated temperature is to 200°C for air cooled specimens there is a decrease in strength up to 910% approximately for M1 mix for a duration of 6 hours, but in case of M2 mix it is 82% and for M3 mix it is 63% maximum for 6 hours duration of exposure. When the concrete mixes M1, M2 and M3 are exposed to 300°C sustained temperature there is a reduction in strength up to 78% for M1 mix for 6 hour duration of exposure.4.2 RESIDUAL COMPRESSIVE STRENGTH VS DURATION OF EXPOSUREFrom Table 1, result shows that heating up to 100°C for 2 hours and 4 hours, the residual strength of mix M1 has decreased where as the residual strength of mix M2 and M3 has increased. The residual strength is further increased for 6 hours duration of exposure in all the three mixes M1, M2 and M3 even beyond the strength at room temperature. When the specimens of mixes M1, M2 and M3 are exposed to 200°C for 2,4 and 6 hours of duration, it is observed that the residual strength has decreased below the room temperature and has reached 92% for M1 mix, 82 and 73% for M2 and M3 mix respectively. Concrete cubes of mixes M1, M2 and M3 when subjected to 300°C temperature for 2,4 and 6 hours the residual strength for mix M1 reduces to 92% for 2 hours up to 78% for six hours duration of exposure, for M2 mix 90% for 2 hours duration of exposure up to 76% for six hour duration of exposure, for M3 mix 88% up to 68% between 2 and 6 hours of duration of exposure.5. IMPACT STRENGTH OF CONCRETE5.1 RESIDUAL IMPACT STRENGTH VS TEMPERATUREFrom the table 1, it can be observed that for the sustained elevated temperature of 100°C the residual impact strength of all the specimens reduces and vary between 20 and 50% for mix M1, 15 to 40% for mix M2 and M3. When the sustained elevated temperature is 200°C the residual impact strength of all the mixes further decreases. The reduction is around 60-70% for mix M1, 55 to 65% for M2 and M3 mix. When the sustained elevated temperature is 300°C it is observed that the residual impact strength reduces further and vary between 85 and 70% for mix M1 and 85 to 90% for mix M2 and mix M3.5.2 RESIDUAL IMPACT STRENGTH VS DURATION OF EXPOSUREFrom the Table 1 and Figures 1 to 3, it can be observed that there is a reduction in impact strength when the sustained elevated temperature is 100°C for 2 hrs, 4 hrs and 6 hrs, and its range is 15 to 50% for all the mixes M1, M2 and M3. The influence of duration of exposure is higher for mix M1 which decreases more rapidly as compared to mix M2 and mix M3 for the same duration of exposure. When the specimens are subjected to sustained elevated temperature of 200°C for 2,4 and 6 hour of duration, further reduction in residual impact strength is observed as compared to at 100°C. The reduction is in the range of 55-70% for all the mixes. The six hour duration of exposure has a greater influence on the residual impact strength of concrete. When the sustained elevated temperature is 300°C for 2,4 and 6 hours duration of exposure the residualimpact strength reduces. It can be seen that both temperature and duration of exposure have a very high influence on the residual impact strength of concrete which shows a reduction up to 90% approximately for all the mixes.6. CONCLUSIONThe compressive strength of concrete increases at 100oC when exposed to sustained elevated temperature. The compressive strength of concrete decreases when exposed to 200°C and 300°C from 10 to 30% for 6 hours of exposure. Residual impact strength reduces irrespective of temperature and duration. Residual impact strength decreases at a higher rate of 20% to 85% as compared to compressive strength between 15% and 30 % when subjected to sustained elevated temperature. The impact strength reduces at a higher rate as compared to compressive strength when subjected to sustained elevated temperature.混凝土受持续高温影响的强度的研究混凝土具有显着的耐火性能。
混凝土专业毕业设计外文翻译---混合物配合比设计[管理资料]
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附录外文翻译MIX DESIGN & PROPORTIONING（一）MIX DESIGNThe concrete mix design (CMD) for QC/QA superstructure concrete must produce a workable concrete mixture having properties that will not exceed the maximum and/or minimum values defined in the special provision. Workability in concrete defines its capacity to be placed, consolidated, and finished without harmful segregation or bleeding. Workability is affected by aggregate gradation, particle shape, proportioning of aggregate, amount and qualities of cementitious materials, presence of entrained air, amount and quality of high range water reducer, and consistency of mixture.Consistency of the concrete mixture is its relative mobility and is measured in terms of slump. The higher the slump the more mobile the concrete, affecting the ease with which the concrete will flow during placement. Consistency is not synonymous with workability. Two different mix designs may have the same slump; however, their workability may be different.Selection of target parameters by the contractor for any mix design must consider the influence of the following:1. material availability and economics2. variability of each material throughout period of usage3. control capability of production plant4. ambient conditions expected at the time(s) of concrete placement5. logistics of concrete production, delivery, and placement6. variability in testing concrete propertiesof heat in large structural elements and differential in thermal gradientThe qualities of the cementitious paste provide a primary influence on the properties of concrete. Proper selection of the cementitious content and water/cementitious ratio is dependent on the experience of the concrete producer and becomes a very important first step in preparing a design. For workable concrete, ahigher water cementitious ratio is typically required when aggregate becomes more angular and rough textured. The presence of air, certain pozzolans, and aggregate proportioning will work to lower the water cementitious ratio; however the most significant reduction in water demand comes through the use of a high range water reducing chemical admixture.Water/cementitious ratio is determined from the net, per unit, quantity of water and total cementitious materials. The net water content excludes water that is absorbed by the aggregates. For a given set of materials and conditions, as water/cementitious ratio increases, strength and unit weight will decrease. Compressive strength is a concrete parameter used in combination with unit weight and air content to evaluate the durability of the superstructure concrete's exposure to freeze / thaw action, and exposure to deicing salts. It is important to note that the designer of the bridge structure does not recognize the benefit of increased compressive strength. The slab still relies on a minimum design compressive strength (f'c) of 4000 psi at 28-days.Proportioning of aggregates is defined by the volume of fine aggregate to the volume of coarse aggregate, as a percent. The lower percentage of fine to total aggregate provides an increase in compressive strength at the expense of workability. The gradation, particle shape and texture of the coarse aggregate along with fineness modulus of the fine aggregate will determine how low the fine to total aggregate percentage can be for a given workability requirement.（二）MIXING PROPORTIONINGOnce the cement content, pozzolan content, water/cementitious ratio, and fine to total aggregate percentage are defined for the concrete's intended use in the superstructure, proportioning of the mix in terms of design batch weights can begin. Specific gravities must be accurately defined for each material being utilized in order to proportion the mix properly by the absolute volume method. Cement is typically accepted as having a specific gravity of . Pozzolans will typically vary between and . Pozzolan suppliers should readily be able to provide current values for their material. Approximate specific gravities are identified for each source on the Department's Approved/Prequalified Materials list; however, they should not be considered the most current.Bulk specific gravity, in the saturated surface dry condition, must be used toproportion the fine and coarse aggregate. Accurate testing of one or more samples of fine and coarse aggregate must be accomplished by the Contractor as part of any proportioning for a mix design. Subsequent shifts in benching at the aggregate source may cause significant shifts in bulk specific gravity and absorption. These are important aggregate properties to monitor as part of concrete quality control.Proportioning concrete by the absolute volume method involves calculating the volume of each ingredient and its contribution to making one y d3or 27 f t3of concrete. V olumes are subsequently converted to design weights, which then become the basis for actual production of concrete from the plant. For cementitious materials and water, the weight to volume conversion is accomplished by dividing the weight (lbs) by the specific gravity of the material and again dividing by the density of water. Converting from volume to weight is accomplished simply by taking the known volume of the ingredient and multiplying by the specific gravity of the ingredient and again multiplying by the density of water. V olume to weight conversions for aggregates are accomplished by the same series of computations; however, bulk specific gravity (SSD) must be used. The target air content is established at % by the special provision, which converts to a volume of f t3within a cubic yard of concrete.（三）LINEAR EQUATION OF UNIT WEIGHT vs. AIR CONTENTIt is known that the unit weight of plastic concrete is inversely proportional to air content. That is to say, as air content increases unit weight decreases. This relationship becomes a very useful tool when evaluating plastic concrete. Unit weight and air content are properties of plastic concrete that can be easily and quickly measured in the field. A unit weight measurement, at a known air content, that deviates excessively from the linear relationship provides information as to the possible deficiencies in the mix and potential effects on properties such as workability, durability, and strength.The linear equation to predict unit weight based on a given air content is presented below in directional form:UW = m (Air) + bWhere: m is the slope of lineAir is the plastic concrete air content (independent variable, xcoordinateor abscissa of point)b is the y-interceptUW is the plastic concrete unit weight (dependent variable, ycoordinate,or ordinate of point)If all points (Air, UW) associated with the solution set of this linear equation were plotted on a graph, there would be a straight line as illustrated by Figure . This linear relationship can be determined for any concrete mix design.（四）THRESHOLD FOR MAXIMUM ALLOWABLE W ATER / CEMENTITIOUS RATIOJust as concrete unit weight is affected by changes in air content, it is also affected by the amount of water that is available to react with cementitious materials. As the amount of water increases the water/cementitious ratio also increases, producing concrete of inferior quality. This serves to lower the concrete unit weight at any given air content. Since the maximum allowable water/cementitious ratio for QC/QA superstructure concrete is , a threshold line or limit can be determined. This threshold line would be parallel to the linear equation for the mix design; however, the unit weight would be lower. The threshold limit has relevancy to results from quality control as well as Acceptance sampling and testing. Should the measured unit weight at any given air content be at or lower than the threshold, it could indicate that the maximum allowable water cementitious ratio was exceeded. It is important to understand that quality control works to center production about the linear equation for the mix design.There are several ways in which additional water could enter a concrete mix. The methodology presented in this chapter assumes that the increase in water/cementitious ratio is due soley to excessive batch water. This provides a simple and accuratedetermination of the threshold limit equation. The methodology begins with the linear equation already established for the mix design. By establishing a single point below the linear equation, representing concrete with excessive water, the equation for threshold limit can be determined. The easiest point to select is at the y-intercept, where the concrete has no entrapped nor entrained air. This point is defined as Point 3, having coordinates (x3, y3). The line for the threshold equation should be parallel to the linear equation for the mix design, which results in the same slope. Knowing the slope and y-intercept the threshold limit equation can then be written.（五）Mix Design & Proportioning WorksheetsIf at least two points are known to be a solution to the equation, algebra can be utilized to solve for the two unknown variables (. slope and y-intercept). The form in Appendix D (under tab 11) entitled "WORKSHEET FOR CMD LINEAR EQUATION" provides the format in which two points can be defined and the equation determined.The Cartesian coordinates of one solution point is already available from the mix design. We can define this as Point 2 with coordinates (x2, y2). The value of x2is the target air content of the mix design (. x2= %). The value of y2is the unit weight of the concrete stated in the mix design. This is determined by obtaining the summation of the design batch weights and dividing by the summation of designabsolute volumes which will always be ft3. The following example calculations for the worksheet are based on the mix design and proportioning values presented earlier in this chapter.Example: x2 = %= Σ Design Batch Weights ÷ ft3y2= 3871 lbs ÷ ft3y2y= lbs/f ft3(rounded to the first decimal place)2A plot of the coordinates for Point 2 (x2= , y2= ) is illustrated in Figure . It is important to note that the unit weight for Point 2 is calculated to the nearest lbs/ ft3 Point 1, representing the y-intercept having coordinates (x1, y1), must now be determined. This is accomplished by theoretically removing all the entrapped and entrained air from the mixture and calculating the concrete unit weight. The value ofx1is % air content. The value of y1is determined by again obtaining the summation of the design batch weights and divide by the summation of design absolute volumes except for entrapped or entrained air. This volume will always be ft3 – ft3= ft3. The following example illustrates how the worksheet calculates the coordinates for Point 1.Example: x1= %y1= Σ Design Batch Weights ÷ ft3y1= 3871 lbs ÷ ft3y1= lbs/ ft3(rounded to the first decimal place)The Cartesian coordinates of Point 1, (x1= ,y1= ), is graphed along with Point 2 in Figure , to illustrate the example. Again note that the unit weight is calculated to the nearest lbs/ ft3It is important to remember that as air is removed from concrete the individual weights of cementitious materials, fine aggregate, coarse aggregate, and water no longer represent amounts relative to yd3of concrete. Concrete without the % target air content ( ft3) would only yield yd3of concrete. The actual cement and water contents per yd3concrete would increase as a result of the under yielding. If air content increases over the % target, the actual cement and water contents per yd3 would be less as a result of the over yielding. However, in either case the water cementitious ratio and fine to total aggregate ratio remain unchanged.From the x and y coordinates of Points 1 & 2, there is now enough information to solve for the variables of slope and y-intercept in the linear equation. The worksheet calculation for slope, also known as "rise / run", is exemplified as follows: Example:slope = m = ( y2 - y1) / (x2 - x1)m = ( – ) / ( – )m = (⎯ ) / ()m = ⎯(negative value, rounded to second decimal place)It is important to note that slope will always be negative since unit weight is inversely proportional to air content.The y-intercept value (b) is simply the ordinate of Point 1, which has already been determined. In the example problem, the worksheet would show the solution b as follows:Example:y-intercept = b = y1b = lbs/ ft3The calculated and rounded values for slope and y-intercept can now be inserted in the linear equation for the variables m and b, respectively. The linear equation can now be written for the concrete mix design. The numbers from the example result in the following:Example:Predicted Unit Weight = m (Air) + bPredicted Unit Weight = ⎯ (Air) +（六）DEPARTMENT CONCURRENCE OF MIX DESIGNIt is the responsibility of the Department's Project Engineer / Project Supervisor to conduct a complete and thorough review of every mix design and proportioning for QC/QA Superstructure Concrete. There is a substantial amount of work that is based on the targets established by the CMD, not the least of which is the linear equation forthe threshold limit that represents the maximum allowable water/cementitious ratio. This threshold limit is of critical importance in determining whether additional cylinders are to be cast as part of an acceptance sample for testing per AASHTO T 277 and subsequent action, which may involve a failed material investigation.The first step in proper review of a CMD is to verify that the materials are from current approved sources. The list of Approved and/or Prequalified Materials is to be used to verify approved sources of cement, fly ash, GGBFS, silica fume, chemical admixtures and air entraining agents. The fine and coarse aggregate ingredients of the concrete mix must be materials from an approved Certified Aggregate Producer. The gradation and quality requirement for the aggregates must also be verified, particularly if stay-in-place metal deck forms are used to facilitate construction of the deck. If AP Quality coarse aggregate is required in the superstructure, the PE/PS will substantiate the quality status. This would include the nature of the mining operations that produce aggregates of the desired quality. The PE/PS should contact the District Materials & Tests Engineer or the District Geologist for confirmation.In addition to the aggregates gradations the PE/PS must verify the bulk specific gravity (SSD) and absorption for the fine and coarse aggregate as being reasonable for the source. If the Contractor's value for absorption differs by more than the multi labortory precision defined within the appropriate test method, the discrepancy will be investigated.The bulk specific gravity and absorption for aggregates are measured by the Department as part of the annual "Summary of Production Quality Results", and periodic Point-Of-Use samples. This data provides the correct basis for comparison of absorption and specific gravity. Figures and graphs of bulk specific gravity (ssd) vs. absorption for a fine and coarse aggregate and are presented as examples of what historical data might look like for specific products at an aggregate source.Usually sources will demonstrate a trend of bulk specific gravity (SSD) being inversely proportional to absorption; however, such may not always be the case. Figure represents data from the INDOT Summary of Production Quality Results for a specific source of #8 coarse aggregate. The AP quality stone comes from ledges 1803, 1804, 19, & 20 processed as one working bench. These four ledges have thicknesses of ft, ft, ft, and ft, respectively. Since these ledges range in absorption from 2 % to 4 %, the consistency of bulk specific gravity and absorption depends on the aggregate source's ability to process the bench in a uniform manner. The District Geologist is the best source for obtaining historical data from "Summary of Production Quality Results" and "Point-of-Use" samples obtained from the aggregate source. They will assist the PE/PS in the proper review of contractor testresults for aggregates.It is important to understand that INDOT historical records for bulk specific gravity (dry or SSD) from coarse aggregate sources are based on procedure of AASHTO T 85. The Contractor must therefore test the coarse aggregate according to the same procedure even though the result is typically not appropriate for concrete mix design. If the mix design is submitted with enough advance notice, it becomes preferable for the Department to obtain a Point-Of-Use sample of the coarse aggregate and test for bulk specific gravity (SSD) by procedure of AASHTO T 85, which is appropriate for concrete mix design. Splitting a sample between the Contractor and the Department to compare test results would be even better.The air entraining and chemical admixtures that are approved for use are as stated in the special provision and the Approved/Prequalified Materials List referenced therein. It is important to recognize the limitations of Type F admixtures or HRWR Admixture Systems. These chemical admixtures have no retarding capability and would not be appropriate for superstructure concrete that is placed in conditions where concrete and ambient temperatures are above 65°F, and where dead load deflections are of concern.After verifying the materials as being approved for the concrete, the initial parameters for the Mix Design must be checked against the specification requirements. The remainder of the PE/PS check involves checking the math for proportioning, and the linear equations for the CMD and threshold limit. Use of the forms and worksheets by the contractor will provide the quickest and most complete review by the Department and therefore help eliminate unnecessary delays by recognizing problems early on.混合物配合比设计（一）混合物设计混凝土配合比设计混凝土质量保证上层建筑（CMD）用于QC /QA必须出示有一个和易性好的混凝土混合物的性能，将不会超过最大和/或最低的特别规定定义的值。
对混凝土结构设计中一些问题的讨论 毕业论文外文文献翻译
Structural design of concrete discussionof some issuesKey words:design; structure calculation; reinforcement structure; protective layer thicknessAbstract: To enable the structural be safe and suitable, economic, and reasonable is a struc tural engineer’s task and responsibility. According to long-term work experience，to introduce the principles of earthquake-resistant design, seismic performance measures to improve housing from the viewpoint of conceptual design. Introduce the environmental categories and the determination of the thickness of protective layer, the calculation of free supported beam settings and the other issues with engineering practice.1.Conceptual Design and Structure,In earthquake-resistant design, there are many factors affect the seismic ability of the whole structure. Such as: The carrying capacity and deformation capacity of structural elements ,the material properties and the provision of energy reserves of non-structural elements; the connection structure; structural stability; the anti-destructive power of the structure’s overall performance under the action of experiencing for the first time earthquake and repeated the role of aftershocks. At present, only the first factor could be calculated, other factors could not be. Only through the conceptual design and structure so that structural system can achieve the necessary bearing capacity, stiffness, stability, the ability of energy absorption and dissipation , that is, sufficient ductility .Of complex structure, One-third calculation, seven parts constructed ,more importantly, is the conceptual design.(1) The Conceptual DesignMaterial properties, component performance, connection structure, structural systems，can be tested through experiments and practice, but can not be calculated, is known as conceptual design. Seismic design should be guided by the following principles: (1) The bearing capacity, stiffness, quality of structure should be symmetrically, uniformly, continuously arranged along the plane and height to avoid the stress concentration；(2) Should set up multi-channel seismic line of defense, arrange statically indeterminate structure and higher ductility components ,pay attention to strengthening the statically determinate structure，the key parts and theweaknesses appropriately; (3) Pay attention to structural integrity of the connection, the same structural unit should be firmly connected while the different structural units should comply with the requirements of the complete separation; (4) Estimation and control of plastic hinge occurs extent and location ，arrange the structure targeted and control the process yield and final yield formation mechanism of the structure; (5) To achieve strong column weak-beam and strong shear weak bending; (6)Take effective measures to prevent the brittle failure such as premature shear break of concrete, anchorage-side sliding of steel and concrete crushing etc; (7) The bearing capacity and stiffness of the connected notes should be compatible with the structure, and the bearing capacity should not less than the structure’s ; (8) The indiscriminate increase in steel consumption should be avoided，if the design bearing of a part is too large or too little may result in the relatively weak of structure, the excessive use of the bending steel of beam end, column end and the strengthening parts of share wall should be reduced when they can meet the requirements of bearing and construction;(9) Consider the beneficial and adverse effects of non-structural components on the main structure.(2) Structure ConstructionStructure systems rely on mechanical calculation to ensure the bearing capacity and deformation, while depend on construction measures to connect the structure elements and form a system. Reasonable constructions can ensure a clear load transfer of components, guarantee the absorption and dissipation of energy under repeated action of force; avoid the loss of carrying capacity and anti-seismic capacity of the entire structural system caused by the destruction of some elements; ensure the durability during design life. We can say that construction is a structural concrete of conceptual design. We have a complete structural construction measures for the pilot study through several decades of practice, especially after learning the experiences and lessons of Tangshan earthquake. The recognize is constantly improved ,the conceptual design is continuously developed, ,we not only need to take proper use of the current measures for structural design and construction, but also need to constantly sum up, enrich and improve our ability.2. Structural calculation(1) The load must be accurateLoads include structural weight, construction materials, equipments loads (equipment weight, pipes weight), building features required live load, wind, snow loads, earthquake forces, temperature changes caused stress, and other incidental roles.Some loads required by specification can be used as the basis, and some need professional advancement. Building professionals need to improve not only the load, but also the practice of specific materials; equipment professionals should provide the selected samples. As construction practices and equipment are generally implemented after ordering while everything may change during the time, so our designers should be aware of it and should have appropriate professional knowledge to calculate the loads accurately. Wall load accounts for a larger percentage of the total loads. Though there are a wide variety of wall materials, there is no ideal one, the load is too large, the soundproof and anti-collision ability are too poor and it will prone to cracks between the plates When the partition walls and the wall materials are identified, the reserved load is necessary; however, considering the large partition wall loads would make the structural steels be excessive, so we generally use lightweight materials and note the wall material, the allowed load and the position in the Construction Drawings with the help of building professionals.Missing the load is the most taboo of the Structure calculation, it will make the calculation be in vain or hide the dangers so we must avoid it.(2) The results should be analyzedWe general need two different cell models to analyze and compare the procedures for Complex or major projects, and should choose a appropriate program for special projects. The model, boundary and supporting conditions all should be realistic. Since it’s essential to improve the design quality, we should clarify the concept and reasons for our input data.(3) The determination of Environmental categories and protective layerThe 3.4.1 stipulation provide the principles for durability design and the classification for environment in the Code for design of concrete structures. In section 9.2.1 shows the minimum thickness of protection layer for longitudinal reinforcements in various types of environment. All of these are specific manifestation of great importance to the durability issue in specification. As the specification is based on the environmental categories to determine the minimum thickness of protective layer of vertical reinforcement, and the side at the junction of the two components of environment, such as the basement walls, the positive side of walls are generally the second-class while its interior side is generally the first-class, the minimum thickness of protection layer of both sides should also be different.So I think, for the component at the junction of the two environment categories, we should depend on the most adverseenvironmental category of the junction in selecting the lowest level and mixing proportion of concrete or in other basic requirements of the durability(3.4.2 ~ 3.4.8 of specification). However, we should determine the thickness of protection layer according with the different categories of environment. Otherwise, for foundation slabs and the basement walls ,when we use the commercial concrete the probability of early contraction will increase as the increase of thickness of protective layer. Therefore, the thickness of protective layer is not the bigger the better and it should be selected by the environmental category of the components’ surfaces exposed.(4) The setting of upper structural steel in the beam end when calculated as free beamIt provides the supper structure reinforcement of the beam end in article 10.2.6 Code for design of concrete structure At this point the end of beam is bound by some constraints, if we analyze it according to the practical constraints by elasticity theory, the moment we get is not only associated with the loads but also with the beam constraints and their relative stiffness. First, it only reflects the loads on beam but doesn’t take the actual restraints of beam end into account, if we associate the reinforcement area with the required use of vertical steel for the lower part of the beam. If the actual constraints are very weak and close to simply supported, the actual moment will be very small even if the load is very great, so we need not configure too many reinforcements. Second, the components partly bind the end of the beam usually refers to the structural column of brick-concrete structure, the edge beam of framework and system of primary and secondary beam. If the actual reinforcement of beam end is large as well as the negative moments of the beam, with a balance, the torque of structural column or edge beams are great. When the binding component is a structural column, its reinforcement is smaller, usually 4φ12, is likely to result in inadequate; when the binding component is the edge beam in a framework or system of primary and secondary beam, although the torque of the edge beams calculated by elastic theory are great, the foreign experimental data shows that, if the edge beam cracked the torsional stiffness is equal to about 1/10 of that of elastical.The result of the re-arranged plastic internal force makes the torque of edge beam and the moment of beam end are very small, so we needn’t to configure too many reinforcements. The actual reinforcement of beam end connected with the edge beam is 2φ12 (4φ12 for limbs hoop),some projects in sixties and seventies on 20th century even use 2φ10 or 2φ8 and they are normally used for more than thirty years.In a word, the strategy given by the specification is still questionable.References:[1] Code for Design of Concrete Structure (GB50010-2002) .2002[2] Chinese Academy of Building Research. Design of Concrete Structure. Press of Chinese Building Industry, .2003High-rise Building (second edition). Press of Wuhan Technology University.2003. [4] PKPM Engineering er Manual and Technical Conditions of SATWE .2003.[5] Technical Specification for Concrete Structures of tall building (JGJ3-2002) .2002对混凝土结构设计中一些问题的讨论关键词:概念设计；结构计算；配筋构造；保护层厚度摘要:使结构安全适用、经济合理、是结构工程师的任务和责任。
混凝土结构设计原理中英文对照版本09Tension Members
9.3 偏心受拉构件斜截面受剪承载力
(b) Ns-Ms 相关关系
第9章
受拉构件
9.3 偏心受拉构件斜截面受剪承载力计算
轴向拉力N的存在，斜裂缝将提前出现，在小偏心受拉情况下 甚至形成贯通全截面的斜裂缝，使斜截面受剪承载力降低。受 剪承载力的降低与轴向拉力N近乎成正比。《规范》对矩形截 面偏心受拉构件受剪承载力
Asv 1.75 V≤ f t bh0 + 1.0 f yv h0 − 0.2 N s λ + 1 .0
9.1
轴心受拉构件
第9章
受拉构件
9.1 轴心受拉构件
N ≤ f y As
N为轴向拉力的设计值； fy为钢筋抗拉强度设计值； As为全部受拉钢筋的截面面积， 应满足As≥ρminA=(0.9ft/fy)A A为构件截面面积。
9.1 轴心受拉构件
第9章
受拉构件
9.2 偏心受拉构件
a' fyA's e' e0 h0-a' fyAs a
第9章 受拉构件
Tension Members
第9章
受拉构件
受拉构件
9.1
轴心受拉构件
第9章
受拉构件
钢筋混凝土桁架或拱拉杆、受内压力作用的环形截 面管壁及圆形贮液池的筒壁等，通常按轴心受拉构 件计算。 矩形水池的池壁、矩形剖面料仓或煤斗的壁板、受 地震作用的框架边柱，以及双肢柱的受拉肢，属于 偏心受拉构件。 偏心受拉构件 受拉构件除轴向拉力外，还同时受弯矩和剪力作用
土木工程混凝土强度中英文对照外文翻译文献
中英文对照外文翻译(文档含英文原文和中文翻译)原文:Strength of Concrete in Slabs, Investigates along Directionof ConcretingABSTRACTIn theory of concrete it is assumed that concrete composites are isotropic on a macro scale. For example, it is assumed that a floor s lab’s or a beam’s strength is identical in all directions and its nonhomogeneity is random. Hence neither calculations of the load-bearing capacity of structural components nor the techniques of investigating concrete in structure in situ take into account to a sufficient degree the fact that the assumption about concrete isotropy is overly optimistic. The present research shows that variation in concrete strengthalong the direction of concreting has not only a qualitative effect (as is commonly believed), but also a significant quantitative effect. This indicates that concrete is a composite which has not been fully understood yet. The paper presents evaluations of ordinary concrete (OC) homogeneity along component thickness along the direction of concreting. The ultrasonic method and modified exponential heads with a point contact with concrete were used in the investigations [1-3].Keywords: Concrete; Compressive Strength of Concrete; Non-Destructive1. IntroductionIn a building structure there are components which are expected to have special properties but not necessarily in the whole cross section. Components under bending, such as beams and floor slabs are generally compressed in their upper zone and the concrete’s compressive strength is vital mainly in this zone. The components are usually moulded in the same position in which they later remain in service, i.e. with their upper zone under compression. Concrete in the upper zone is expected to be slightly weaker than in the lower zone, but it is unclear how much weaker [4,5]. Also flooring slabs in production halls are most exposed to abrasion and impact loads in their upper zone which is not their strongest part. It is known from practice that industrial floors belong to the most often damaged building components.When reinforced concrete beams or floor slabs are to be tested they can be accessed only from their undersides and so only the bottom parts are tested and on this basis conclusions are drawn about the strength of the concrete in the whole cross section, including in the compressed upper zone. Thus a question arises: how large are the errors committed inthis kind of investigations?In order to answer the above and other questions, tests of the strength of concrete in various structural components, especially in horizontally concreted slabs, were carried out. The variation of strength along the thickness of the components was analyzed.2. Research SignificanceThe research results presented in the paper show that the compressive strength of concrete in horizontally formed structural elements varies along their thickness. In the top zone the strength is by 25% - 30% lower than the strength in the middle zone, and it can be by as much as 100% lower than the strength in the bottom zone. The observations are based on the results of nondestructive tests carried out on drill cores taken from the structure, and verified by a destructive method. It is interesting to note that despite the great advances in concrete technology, the variation in compressive strength along the thickness of structural elements is characteristic of both old (over 60 years old) concretes and contemporary ordinary concretes.3. Test MethodologyBefore Concrete strength was tested by the ultrasonic method using exponential heads with a point contact with concrete. The detailed specifications of the heads can be found in [2,3]. The heads’ frequency was 40 and 100 kHz and the diameter of their concentrators amounted to 1 mm.In order to determine the real strength distributions in the existing structures, cylindrical cores 80 mm or 114 mm diameter (Figure 2) were drilled from them in the direction of concreting. Then specimens with their height equal to their diameter were cut out of the cores.Ultrasonic measurements were performed on the cores according to the scheme shown in Figure 3. Ultrasonic pulses (pings) were passed through in two perpendicular directions I and II in planes spaced every 10 mm. In this way one could determine how ping velocity varied along the core’s height, i.e. along the thickness of the tested component.In both test directions ping pass times were determined and velocities CL were calculated. The velocities from the two directions in a tested measurement plane were averaged.Subsequently, specimens with their height equal to their diameter of 80 mm were cut out of the cores. Aver-age ultrasonic pulse velocity CL for the specimen’s central zone was correlated with fatigue strength fc determined by destructive tests carried out in a strength tester.For the different concretes different correlation curves with a linear, exponential orpower equation were obtained. Exemplary correlation curve equations are given below:Lc c L c C f L f C f 38.1exp 0951.01.003.56705.232621.4=⋅=-⨯=where: fc —the compressive strength of concrete MPa,CL —ping velocity km/s.The determined correlation curve was used to calculate the strength of concrete in each tested core cross section and the results are presented in the form of graphs illustrating concrete strength distribution along the thickness of the tested component.4. Investigation of Concrete in Industrial FloorsAfter Floor in sugar factory’s raw materials storage hall Concrete in an industrial floor must have particularly good characteristics in the top layer. Since it was to be loaded with warehouse trucks and stored sugar beets and frequently washed the investigated concretefloor (built in 1944) was designed as consisting of a 150 mm thick underlay and a 50 mm thick surface layer and made of concrete with a strength of 20 MPa (concrete A).As part of the investigations eight cores, each 80 mm in diameter, were drilled from the floor. The investigations showed significant departures from the design. The concrete subfloor’s thickness varied from 40 to 150 mm. The surface layer was not made of concrete, but of cement mortar with sand used as the aggregate. Also the thickness of this layer was uneven, varying from 40 to 122mm. After the ultrasonic tests specimens with their height equal to their diameter of 80 mm were cut out of the cores. Two scaling curves: one for the surface layer and the other for the bottom concrete layer were determined.A characteristic concrete compressive strength distribution along the floor’s thickness is shown in Figure 4.Strength in the upper zone is much lower than in the lower zone: ranging from 4.7 to 9.8 MPa for the mortar and from 13.9 to 29.0 MPa for the concrete layer. The very low strength of the upper layer of mortar is the result of strong porosity caused by air bubbles escaping upwards during the vibration of co ncrete. Figure 5 shows the specimen’s porous top surface.Floor in warehouse hall with forklift truck transport The floor was built in 1998. Cellular concrete was used as for the underlay and the 150 mm thick surface layer was made of ordinary concrete with fibre (steel wires) reinforcement (concrete B). Cores 80 mm high and 80 mm in diameter were drilled from the surface layer. Ultrasonic measurements and destructive tests were performed as described above. Also the test results were handled in a similar way. An exemplary strength distribution along the floor’s thickness is shown in Figure 6.5. ConclusionsTests of ordinary concretes show unexpectedly greatly reduced strength in the upper zone of horizontally moulded structural components. This is to a large degree due to thevibration of concrete as a result of which coarse aggregate displaces downwards making the lower layers more compact while air moves upwards aerating the upper layers and thereby increasing their porosity. The increase in the concre te’s porosity results in a large drop in its compressive strength. Thanks to the use of the ultrasonic method and probes with exponential concentrators it could be demonstrated how the compressive strength of ordinary concrete is distributed along the thickness of structural components in building structures. It became apparent that the reduction in compressive strength in the compressed zone of structural components under bending and in industrial concrete floors can be very large (amounting to as much as 50% of the strength of the slab’s lower zone). Therefore this phenomenon should be taken into account at the stage of calculating slabs, reinforced concrete beams and industrial floors [6].The results of the presented investigations apply to ordinary concretes (OC) which are increasingly supplanted by self-compacting concretes (SCC) and high-performance concretes (HPC). Since no intensive vibration is required to mould structures from such concretes one can expect that they are much more homogenous along their thickness [7]. This will be known once the ongoing experimental research is completed.Bohdan StawiskiStrength of Concrete in Slabs, Investigates along Direction of Concreting[D]Institute of Building Engineering, Wroclaw University of Technology Wybrzeze Wyspianskiego, Wroclaw, PolandReceived October 15, 2011; revised November 21, 2011; accepted November 30, 2011译文:混凝土强度与混凝土浇筑方向关系的研究摘要从理论上看，假设混凝土复合材料是各项同性的从宏观尺度上讲。
土木工程 建筑 外文翻译 外文文献 英文文献 钢筋混凝土及土方工程简介[策划]
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土木工程建筑外文翻译外文文献英文文献钢筋混凝土及土方工程简介[策划]2 外文翻译Introduction to reinforced concrete and earthworks:Abstract As a designer must first clear the building structureitself was designed and intensity levels, as well as related issues in-depth discussion and research, this paper describes on the reinforced concrete, earthwork engineering knowledge, let more in-depth understanding of this Discusses the key, and the rational application of knowledge to help us design more excellent buildingKeywords: concrete, earthwork, structural safety2.1 Reinforced ConcretePlain concrete is formed from a hardened mixture ofcement ,water ,fine aggregate, coarse aggregate (crushed stone or gravel),air, and often other admixtures. The plastic mix is placed and consolidated in the formwork, then cured to facilitate the acceleration of the chemical hydration reaction lf the cement/water mix, resulting in hardened concrete. The finished product has high compressive strength, and low resistance to tension, such that its tensile strength is approximately one tenth lf its compressive strength. Consequently, tensile and shear reinforcement in the tensile regions of sections hasto be provided to compensate for the weak tension regions in the reinforced concrete element.It is this deviation in the composition of a reinforces concrete section from the homogeneity of standard wood or steel sections that requires a modified approach to the basic principles of structural design. The two components of the heterogeneous reinforced concrete section are to be so arranged and proportioned that optimal use is made of the materials involved. This is possible becauseconcrete can easily be given any desired shape by placing and compacting the wet mixture of the constituent ingredients are properly proportioned, the finished product becomes strong, durable, and, in combination with the reinforcing bars, adaptable for use as main members of any structural system.The techniques necessary for placing concrete depend on the type of member to be cast: that is, whether it is a column, a bean, a wall, a slab, a foundation. a mass columns, or an extension of previously placed and hardened concrete. For beams, columns, and walls, the forms should be well oiled after cleaning them, and the reinforcement should be cleared of rust and other harmful materials. In foundations, the earth should be compacted and thoroughly moistened to about 6 in. in depth to avoid absorption of the moisture present in the wet concrete. Concrete should always be placed in horizontal layers which are compacted by means of high frequency power-driven vibrators of either the immersion or external type, as the case requires, unless it is placed by pumping.It must be kept in mind, however, that over vibration can be harmful since it could causesegregation of the aggregate and bleeding of the concrete.Hydration of the cement takes place in the presence of moisture at temperatures above 50?F. It is necessary to maintain such a condition in order that the chemical hydration reaction can take place. If drying is too rapid, surface cracking takes place. This would result in reduction of concrete strength due to cracking as well as the failure to attain full chemical hydration.It is clear that a large number of parameters have to be dealt with in proportioning a reinforced concrete element, such as geometrical width, depth, area of reinforcement, steel strain, concrete strain,steel stress, and so on. Consequently, trial and adjustment is necessary in the choice of concrete sections, with assumptions based on conditions at site, availability of the constituent materials, particular demands of the owners, architectural and headroom requirements, the applicable codes, and environmental reinforced concrete is often a site-constructed composite, in contrast to the standard mill-fabricated beam and column sections in steel structures.A trial section has to be chosen for each critical location in a structural system. The trial section has to be analyzed to determine if its nominal resisting strength is adequate to carry the applied factored load. Since more than one trial is often necessary to arrive at the required section, the first design input step generates intoa series of trial-and-adjustment analyses.The trial-and –adjustment procedures for the choice of a concrete section lead to the convergence of analysis and design. Hence every design is an analysis once a trial section is chosen. The availability of handbooks, charts, and personal computers and programs supports this approach as a more efficient, compact, and speedy instructional method compared with the traditional approach of treating the analysis of reinforced concrete separately from pure design.2.2 EarthworkBecause earthmoving methods and costs change more quickly than those in any other branch of civil engineering, this is a field where there are real opportunities for the enthusiast. In 1935 most of the methods now in use for carrying and excavating earth with rubber-tyred equipment did not exist. Most earth was moved by narrow rail track, now relatively rare, and the main methods of excavation, with face shovel, backacter, or dragline or grab, though they are still widely used are only a few of the many current methods. To keep his knowledge of earthmoving equipment up to date an engineer must therefore spend tine studying modern machines. Generally the only reliable up-to-date information on excavators, loaders and transport is obtainable from the makers.Earthworks or earthmoving means cutting into ground where itssurface is too high ( cuts ), and dumping the earth in other places where the surface is too low ( fills). Toreduce earthwork costs, the volume of the fills should be equal to the volume of the cuts andwherever possible the cuts should be placednear to fills of equal volume so as to reduce transport and double handlingof the fill. This work of earthwork design falls on the engineer who lays out the road since it is the layout of the earthwork more than anything else which decides its cheapness. From the available maps ahd levels, the engineering must tryto reach as many decisions as possible in the drawing office by drawing cross sections of the earthwork. On the site when further information becomes available he can make changes in jis sections and layout,but the drawing lffice work will not have been lost. It will have helped him to reach the best solution in the shortest time.The cheapest way of moving earth is to take it directly out of thecut and drop it as fill with the same machine. This is not always possible, but when it canbe done it is ideal, being both quick and cheap. Draglines, bulldozers and face shovels an dothis. The largest radius is obtained with the dragline,and thelargest tonnage of earth is moved by the bulldozer, though only overshort distances.The disadvantages of the dragline are that it must dig below itself, it cannot dig with force into compacted material, itcannot dig on steep slopws, and its dumping and digging are not accurate.Face shovels are between bulldozers and draglines, having a larger radius of action than bulldozers but less than draglines. They are anleto dig into a vertical cliff face in a way which would be dangerous tora bulldozer operator and impossible for a dragline. Each piece of equipment should be level of their tracks and for deep digs in compactmaterial a backacter is most useful, but its dumping radius is considerably less than that of the same escavator fitted with a face shovel.Rubber-tyred bowl scrapers are indispensable for fairly leveldigging where the distance of transport is too much tor a dragline or face shovel. They can dig the material deeply ( but only below themselves ) to a fairly flat surface, carry it hundreds of meters if need be, then drop it and level it roughly during the dumping. For hard digging it is often found economical to keep a pusher tractor ( wheeled or tracked ) on the digging site, to push each scraper as it returns to dig. As soon as the scraper is full,the pusher tractor returns to the beginning of the dig to heop to help the nest scraper.Bowl scrapers are often extremely powerful machines;many makersbuild scrapers of 8 cubic meters struck capacity, which carry 10 m ? heaped. The largest self-propelled scrapers are of 19 m ? struck capacity ( 25 m ? heaped )and they are driven by a tractor engine of 430 horse-powers.Dumpers are probably the commonest rubber-tyred transport since they can also conveniently be used for carrying concrete or other building materials. Dumpers have the earth container over the front axle on large rubber-tyred wheels, and the container tips forwards on most types, though in articulated dumpers the direction of tip can be widely varied. The smallest dumpers have a capacity of about 0.5 m ?, and the largest standard types are of about 4.5 m ?. Special types include the self-loading dumper of up to 4 m ? and the articulated type of about 0.5 m ?. The distinction between dumpers and dump trucks must beremembered .dumpers tip forwards and the driver sits behind the load. Dump trucks are heavy,strengthened tipping lorries, the driver travels in front lf theload and the load is dumped behind him, so they are sometimes called rear-dump trucks.2.3 Safety of StructuresThe principal scope of specifications is to provide generalprinciples and computational methods in order to verify safety of structures. The “ safety factor ”, which according to modern trends is independent of the nature and combination of the materials used, can usually be defined as the ratio between the conditions. This ratio is also proportional to the inverse of the probability ( risk ) of failure of the structure.Failure has to be considered not only as overall collapse of the structure but also as unserviceability or, according to a more precise. Common definition. As the reaching of a “ limit state ” which causes the construction not to accomplish the task it was designed for. There are two categories of limit state :(1)Ultimate limit sate, which corresponds to the highest value ofthe load-bearing capacity. Examples include local buckling or global instability of the structure; failure of some sections and subsequent transformation of the structure into a mechanism; failure by fatigue;elastic or plastic deformation or creep that cause a substantial change of the geometry of the structure; and sensitivity of the structure to alternating loads, to fire and to explosions.(2)Service limit states, which are functions of the use anddurability of the structure. Examples include excessive deformations and displacements without instability; early or excessive cracks; large vibrations; and corrosion.Computational methods used to verify structures with respect to the different safety conditions can be separated into:(1)Deterministic methods, in which the main parameters are considered as nonrandom parameters.(2)Probabilistic methods, in which the main parameters are considered as random parameters.Alternatively, with respect to the different use of factors of safety, computational methods can be separated into:(1)Allowable stress method, in which the stresses computed under maximumloads are compared with the strength of the material reduced bygiven safety factors.(2)Limit states method, in which the structure may be proportionedon the basis of its maximum strength. This strength, as determined by rational analysis, shall not be less than that required to support a factored load equal to the sum of the factored live load and dead load ( ultimate state ).The stresses corresponding to working ( service ) conditions with unfactored live and dead loads are compared with prescribed values( service limit state ) . From the four possible combinations of thefirst two and second two methods, we can obtain some usefulcomputational methods. Generally, two combinations prevail:(1)deterministic methods, which make use of allowable stresses.(2)Probabilistic methods, which make use of limit states.The main advantage of probabilistic approaches is that, at least in theory, it is possible to scientifically take into account all random factors of safety, which are then combined to define the safety factor. probabilistic approaches depend upon :(1) Random distribution of strength of materials with respect to the conditions of fabrication and erection ( scatter of the values of mechanical properties through out the structure );(2) Uncertainty of the geometry of the cross-section sand of the structure ( faults and imperfections due to fabrication and erection of the structure );(3) Uncertainty of the predicted live loads and dead loads acting on the structure;(4)Uncertainty related to the approximation of the computational method used ( deviation of the actual stresses from computed stresses ).Furthermore, probabilistic theories mean that the allowable risk can be based on several factors, such as :(1) Importance of the construction and gravity of the damage by its failure;(2)Number of human lives which can be threatened by this failure;(3)Possibility and/or likelihood of repairing the structure;(4) Predicted life of the structure.All these factors are related to economic and social considerations such as:(1) Initial cost of the construction;(2) Amortization funds for the duration of the construction;(3) Cost of physical and material damage due to the failure of the construction;(4) Adverse impact on society;(5) Moral and psychological views.The definition of all these parameters, for a given safety factor, allows construction at the optimum cost. However, the difficulty of carrying out a complete probabilistic analysis has to be taken into account. For such an analysis the laws of the distribution of the live load and its induced stresses, of the scatter of mechanical properties of materials, and of the geometry of the cross-sections and the structure have to be known. Furthermore, it is difficult to interpret the interaction between the law of distribution of strength and that of stresses because both depend upon the nature of the material, on the cross-sections and upon the load acting on the structure. These practical difficulties can be overcome in two ways. The first is toapply different safety factors to the material and to the loads, without necessarily adopting the probabilistic criterion. The second is an approximate probabilistic method which introduces some simplifying assumptions ( semi-probabilistic methods ) .References:1. Hanjing Yun. Building decoration materials and their application. China Building Industry Press .2000.2. Xia Yan eds. Civil engineering materials. Wuhan UniversityPress .2009.3. From before the king, Huoman Lin. Building materials (first edition). Lanzhou University Press .19974. Zhang Xiong editor. Building functional materials. China Building Industry Press .2000.5. Yanhan Dong, Qian Xiao Qian ed. New Building Materials tutorial. China Building Materials Industry Press .2005.6. Zhang Fen Qin, Zhao Man ed. Building decoration materials. Chongqing University Press, .2007.7. Xuyou Hui ed. Building materials and learning. Southwest Jiaotong University Press .2007.1 中文翻译钢筋混凝土及土方工程简介摘要:作为设计人员首先必须明确自身设计的建筑构筑物得等级和强度，以及对相关问题进行深入的讨论和研究，本文主要叙述了关于钢筋混凝土，土方工程方面的相关知识，让我们更加深入的了解这方面的主要关键论述，以及合理应用知识来帮助我们设计更加优良的建筑。
土木工程专业外文翻译--钢筋混凝土结构设计
外文原文：Design of Reinforced Concrete StructuresSecond Edition(USA) Williams·Alan2Structure in Design of Architecture And StructuralMaterial，China Water Power Press，Beijing,2002. P37～57钢筋混凝土结构设计第二版(美)艾伦·威廉斯著第二章，在建筑学的设计构成和结构的材料，中国水利水电出版社，北京,2002.P37页～57页.Structure in Design of Architecture And Structural Material We have and the architects must deal with the spatial aspect of activity, physical, and symbolic needs in such a way that overall performance integrity is assured. Hence, he or she well wants to think of evolving a building environment as a total system of interacting and space forming subsystems. Is represents a complex challenge, and to meet it the architect will need a hierarchic design process that provides at least three levels of feedback thinking: schematic, preliminary, and final.Such a hierarchy is necessary if he or she is to avoid being confused , atconceptual stages of design thinking ,by the myriad detail issues that candistract attention from more basic considerations .In fact , we can say thatan architect’s ability to distinguish the more basic form the more detailedissues is essential to his success as a designer .The object of the schematic feed back level is to generate and evaluate overallsite-plan, activity-interaction, and building-configuration options .To do sothe architect must be able to focus on the interaction of the basic attributes of the site context, the spatial organization, and the symbolism as determinants of physical form. This means that ,in schematic terms ,the architect may first conceive and model a building design as an organizational abstraction of essential performance-space in teractions.Then he or she may explore the overall space-form implications of the abstraction. As an actual building configuration option begins to emerge, it will be modified to include consideration for basic site conditions.At the schematic stage, it would also be helpful if the designer could visualize his or her options for achieving overall structural integrity and consider the constructive feasibility and economic of his or her scheme .But this will require that the architect and/or a consultant be able to conceptualize total-system structural options in terms of elemental detail .Such overall thinking can be easily fed back to improve the space-form scheme.At the preliminary level, the architect’s emphasis will shift to the elaboration of his or her more promising schematic design options .Here the architect’s structural needs will shift to approximate design of specific subsystem options. At this stage the total structural scheme is developed to a middle level of specificity by focusing on identification and design of major subsystems to the extent that their key geometric, component, and interactive properties are established .Basic subsystem interaction and design conflicts can thus be identified and resolved in the context of total-system objectives. Consultants can play a significant part in this effort; these preliminary-level decisions may also result in feedback that calls for refinement or even major change in schematic concepts.When the designer and the client are satisfied with the feasibility of a design proposal at the preliminary level, it means that the basic problems of overall design are solved and details are not likely to produce major change .The focus shifts again ,and the design process moves into the final level .At this stagethe emphasis will be on the detailed development of all subsystem specifics . Here the role of specialists from various fields, including structural engineering, is much larger, since all detail of the preliminary design must be worked out. Decisions made at this level may produce feedback into Level II that will result in changes. However, if Levels I and II are handled with insight, the relationship between the overall decisions, made at the schematic and preliminary levels, and the specifics of the final level should be such that gross redesign is not in question, Rather, the entire process should be one of moving in an evolutionary fashion from creation and refinement (or modification) of the more general properties of a total-system design concept, to the fleshing out of requisite elements and details.To summarize: At Level I, the architect must first establish, in conceptual terms, the overall space-form feasibility of basic schematic options. At this stage, collaboration with specialists can be helpful, but only if in the form of overall thinking. At Level II, the architect must be able to identify the major subsystem requirements implied by the scheme and substantial their interactive feasibility by approximating key component properties .That is, the properties of major subsystems need be worked out only in sufficient depth to very the inherent compatibility of their basic form-related and behavioral interaction . This will mean a somewhat more specific form of collaboration with specialists then that in level I .At level III ,the architect and the specific form of collaboration with specialists then that providing for all of the elemental design specifics required to produce biddable construction documents . Of course this success comes from the development of the Structural Material. The principal construction materials of earlier times were wood and masonry brick, stone, or tile, and similar materials. The courses or layers were bound together with mortar or bitumen, a tar like substance, or some other binding agent. The Greeks and Romans sometimes used iron rods or claps to strengthen their building. The columns of the Parthenon in Athens, for example, have holes drilled in themfor iron bars that have now rusted away. The Romans also used a natural cement called puzzling, made from volcanic ash, that became as hard as stone under water. Both steel and cement, the two most important construction materials of modern times, were introduced in the nineteenth century. Steel, basically an alloy of iron and a small amount of carbon had been made up to that time by a laborious process that restricted it to such special uses as sword blades. After the invention of the Bessemer process in 1856, steel was available in large quantities at low prices. The enormous advantage of steel is its tensile force which, as we have seen, tends to pull apart many materials. New alloys have further, which is a tendency for it to weaken as a result of continual changes in stress.Modern cement, called Portland cement, was invented in 1824. It is a mixture of limestone and clay, which is heated and then ground into a power. It is mixed at or near the construction site with sand, aggregate small stones, crushed rock, or gravel, and water to make concrete. Different proportions of the ingredients produce concrete with different strength and weight. Concrete is very versatile; it can be poured, pumped, or even sprayed into all kinds of shapes. And whereas steel has great tensile strength, concrete has great strength under compression. Thus, the two substances complement each other.They also complement each other in another way: they have almost the same rate of contraction and expansion. They therefore can work together in situations where both compression and tension are factors. Steel rods are embedded in concrete to make reinforced concrete in concrete beams or structures where tensions will develop. Concrete and steel also form such a strong bond─ the force that unites them─ that the steel cannot slip within the concrete. Still another advantage is that steel does not rust in concrete. Acid corrodes steel, whereas concrete has an alkaline chemical reaction, the opposite of acid. The adoption of structural steel and reinforced concrete caused major changes in traditional construction practices. It was no longer necessary to use thickwalls of stone or brick for multistory buildings, and it became much simpler to build fire-resistant floors. Both these changes served to reduce the cost of construction. It also became possible to erect buildings with greater heights and longer spans.Since the weight of modern structures is carried by the steel or concrete frame, the walls do not support the building. They have become curtain walls, which keep out the weather and let in light. In the earlier steel or concrete frame building, the curtain walls were generally made of masonry; they had the solid look of bearing walls. Today, however, curtain walls are often made of lightweight materials such as glass, aluminum, or plastic, in various combinations.Another advance in steel construction is the method of fastening together the beams. For many years the standard method was riveting. A rivet is a bolt with a head that looks like a blunt screw without threads. It is heated, placed in holes through the pieces of steel, and a second head is formed at the other end by hammering it to hold it in place. Riveting has now largely been replaced by welding, the joining together of pieces of steel by melting a steel material between them under high heat.Priestess’s concrete is an improved form of reinforcement. Steel rods are bent into the shapes to give them the necessary degree of tensile strengths. They are then used to priestess concrete, usually by one of two different methods. The first is to leave channels in a concrete beam that correspond to the shapes of the steel rods. When the rods are run through the channels, they are then bonded to the concrete by filling the channels with grout, a thin mortar or binding agent. In the other (and more common) method, the priestesses steel rods are placed in the lower part of a form that corresponds to the shape of the finished structure, and the concrete is poured around them. Priestess’s concrete uses less steel and less concrete. Because it is a highly desirable material. Progressed concrete has made it possible to develop buildings with unusualshapes, like some of the modern, sports arenas, with large spaces unbroken by any obstructing supports. The uses for this relatively new structural method are constantly being developed.中文译文：在建筑学的设计构成和结构的材料我们有，并且建筑师一定在一个如此的方法中处理活动，身体检查和代号需要的空间方面全部的表现正直被保证。
外文翻译---钢筋混凝土结构设计制约因素(部分)
外文资料翻译The constraintion of reinforced concrete structure design ( part)Part 1. Reinforced ConcretePlain concrete is formed from a hardened mixture of cement ,water ,fine aggregate, coarse aggregate (crushed stone or gravel),air, and often other admixtures. The plastic mix is placed and consolidated in the formwork, then cured to facilitate the acceleration of the chemical hydration reaction lf the cement/water mix, resulting in hardened concrete. The finished product has high compressive strength, and low resistance to tension, such that its tensile strength is approximately one tenth lf its compressive strength. Consequently, tensile and shear reinforcement in the tensile regions of sections has to be provided to compensate for the weak tension regions in the reinforced concrete element.It is this deviation in the composition of a reinforces concrete section from the homogeneity of standard wood or steel sections that requires a modified approach to the basic principles of structural design. The two components of the heterogeneous reinforced concrete section are to be so arranged and proportioned that optimal use is made of the materials involved. This is possible because concrete can easily be given any desired shape by placing and compacting the wet mixture of the constituent ingredients are properly proportioned, the finished product becomes strong, durable, and, in combination with the reinforcing bars, adaptable for use as main members of any structural system.The techniques necessary for placing concrete depend on the type of member to be cast: that is, whether it is a column, a bean, a wall, a slab, a foundation. a mass columns, or an extension of previously placed and hardened concrete. For beams, columns, and walls, the forms should be well oiled after cleaning them, and the reinforcement should be cleared of rust and other harmful materials. In foundations, the earth should be compacted and thoroughly moistened to about 6 in. in depth to avoid absorption of the moisture present in the wet concrete. Concrete should always be placed in horizontal layers which are compacted by means of high frequency power-driven vibrators of either the immersion or external type, as the case requires, unless it is placed by pumping. It must be kept in mind, however, that over vibration can be harmful since it could cause segregation of the aggregate and bleeding of the concrete.Hydration of the cement takes place in the presence of moisture at temperatures above 50°F. It is necessary to maintain such a condition in order that the chemical hydration reaction can take place. If drying is too rapid, surface cracking takes place. This would result in reduction of concrete strength due to cracking as well as the failure to attain full chemical hydration.It is clear that a large number of parameters have to be dealt with in proportioning a reinforced concrete element, such as geometrical width, depth, area of reinforcement, steel strain, concrete strain, steel stress, and so on. Consequently, trial and adjustment is necessary in the choice of concrete sections, with assumptionsbased on conditions at site, availability of the constituent materials, particular demands of the owners, architectural and headroom requirements, the applicable codes, and environmental reinforced concrete is often a site-constructed composite, in contrast to the standard mill-fabricated beam and column sections in steel structures.A trial section has to be chosen for each critical location in a structural system. The trial section has to be analyzed to determine if its nominal resisting strength is adequate to carry the applied factored load. Since more than one trial is often necessary to arrive at the required section, the first design input step generates into a series of trial-and-adjustment analyses.The trial-and –adjustment procedures for the choice of a concrete section lead to the convergence of analysis and design. Hence every design is an analysis once a trial section is chosen. The availability of handbooks, charts, and personal computers and programs supports this approach as a more efficient, compact, and speedy instructional method compared with the traditional approach of treating the analysis of reinforced concrete separately from pure design.Part 2 Safety of StructuresThe principal scope of specifications is to provide general principles and computational methods in order to verify safety of structures. The “ safety factor ”, which according to modern trends is independent of the nature and combination of the materials used, can usually be defined as the ratio between the conditions. This ratio is also proportional to the inverse of the probability ( risk ) of failure of the structure.Failure has to be considered not only as overall collapse of the structure but also as unserviceability or, according to a more precise. Common definition. As the reaching of a “ limit state ” which causes the construction not to accomplish the task it was designed for. There are two categories of limit state :(1)Ultimate limit sate, which corresponds to the highest value of the load-bearing capacity. Examples include local buckling or global instability of the structure; failure of some sections and subsequent transformation of the structure into a mechanism; failure by fatigue; elastic or plastic deformation or creep that cause a substantial change of the geometry of the structure; and sensitivity of the structure to alternating loads, to fire and to explosions.(2)Service limit states, which are functions of the use and durability of the structure. Examples include excessive deformations and displacements without instability; early or excessive cracks; large vibrations; and corrosion.Computational methods used to verify structures with respect to the different safety conditions can be separated into:(1)Deterministic methods, in which the main parameters are considered as nonrandom parameters.(2)Probabilistic methods, in which the main parameters are considered as random parameters.Alternatively, with respect to the different use of factors of safety, computational methods can be separated into:(1)Allowable stress method, in which the stresses computed under maximum loads are compared with the strength of the material reduced by given safety factors.(2)Limit states method, in which the structure may be proportioned on the basis of its maximum strength. This strength, as determined by rational analysis, shall not be less than that required to support a factored load equal to the sum of the factored live load and dead load ( ultimate state ).The stresses corresponding to working ( service ) conditions with unfactored live and dead loads are compared with prescribed values ( service limit state ) . From the four possible combinations of the first two and second two methods, we can obtain some useful computational methods. Generally, two combinations prevail:(1)deterministic methods, which make use of allowable stresses.(2)Probabilistic methods, which make use of limit states.The main advantage of probabilistic approaches is that, at least in theory, it is possible to scientifically take into account all random factors of safety, which are then combined to define the safety factor. probabilistic approaches depend upon :(1) Random distribution of strength of materials with respect to the conditions of fabrication and erection ( scatter of the values of mechanical properties through out the structure );(2) Uncertainty of the geometry of the cross-section sand of the structure ( faults and imperfections due to fabrication and erection of the structure );(3) Uncertainty of the predicted live loads and dead loads acting on the structure;(4)Uncertainty related to the approximation of the computational method used ( deviation of the actual stresses from computed stresses ).Furthermore, probabilistic theories mean that the allowable risk can be based on several factors, such as :(1) Importance of the construction and gravity of the damage by its failure;(2)Number of human lives which can be threatened by this failure;(3)Possibility and/or likelihood of repairing the structure;(4) Predicted life of the structure.All these factors are related to economic and social considerations such as：(1) Initial cost of the construction;(2) Amortization funds for the duration of the construction;(3) Cost of physical and material damage due to the failure of the construction;(4) Adverse impact on society;(5) Moral and psychological views.The definition of all these parameters, for a given safety factor, allows construction at the optimum cost. However, the difficulty of carrying out a complete probabilistic analysis has to be taken into account. For such an analysis the laws of the distribution of the live load and its induced stresses, of the scatter of mechanical properties of materials, and of the geometry of the cross-sections and the structure have to be known. Furthermore, it is difficult to interpret the interaction between the law of distribution of strength and that of stresses because both depend upon the nature of the material, on the cross-sections and upon the load acting on the structure. These practical difficulties can be overcome in two ways. The first is to apply different safety factors to the material and to the loads, without necessarily adopting the probabilistic criterion. The second is an approximate probabilistic method whichintroduces some simplifying assumptions.钢筋混凝土结构设计制约因素（部分）第一部分：钢筋混凝土混凝土是由水泥、水、细骨料、粗骨料（碎石或；卵石）、空气，通常还有其他外加剂等经过凝固硬化而成。
建筑类外文文献及中文翻译
forced concrete structure reinforced with anoverviewReinSince the reform and opening up, with the national economy's rapid and sustained development of a reinforced concrete structure built, reinforced with the development of technology has been great. Therefore, to promote the use of advanced technology reinforced connecting to improve project quality and speed up the pace of construction, improve labor productivity, reduce costs, and is of great significance.Reinforced steel bars connecting technologies can be divided into two broad categories linking welding machinery and steel. There are six types of welding steel welding methods, and some apply to the prefabricated plant, and some apply to the construction site, some of both apply. There are three types of machinery commonly used reinforcement linking method primarily applicable to the construction site. Ways has its own characteristics and different application, and in the continuous development and improvement. In actual production, should be based on specific conditions of work, working environment and technical requirements, the choice of suitable methods to achieve the best overall efficiency.1、steel mechanical link1.1 radial squeeze linkWill be a steel sleeve in two sets to the highly-reinforced Department with superhigh pressure hydraulic equipment (squeeze tongs) along steel sleeve radial squeeze steel casing, in squeezing out tongs squeeze pressure role of a steel sleeve plasticity deformation closely integrated with reinforced through reinforced steel sleeve and Wang Liang's Position will be two solid steel bars linkedCharacteristic: Connect intensity to be high, performance reliable, can bear high stress draw and pigeonhole the load and tired load repeatedly.Easy and simple to handle, construction fast, save energy and material, comprehensive economy profitable, this method has been already a large amount of application in the project.Applicable scope : Suitable for Ⅱ, Ⅲ, Ⅳgrade reinforcing bar (including welding bad reinfor cing bar ) with ribbing of Ф 18- 50mm, connection between the same diameter or different diameters reinforcing bar .1.2must squeeze linkExtruders used in the covers, reinforced axis along the cold metal sleeve squeeze dedicated to insert sleeve Lane two hot rolling steel drums into a highly integrated mechanical linking methods.Characteristic: Easy to operate and joining fast and not having flame homework , can construct for 24 hours , save a large number of reinforcing bars and energy. Applicable scope : Suitable for , set up according to first and second class antidetonation requirement -proof armored concrete structure ФⅡ, Ⅲgrade reinforcing bar with ribbing of hot rolling of 20- 32mm join and construct live.1.3 cone thread connectingUsing cone thread to bear pulled, pressed both effort and self-locking nature, undergo good principles will be reinforced by linking into cone-processing thread at the moment the value of integration into the joints connecting steel bars.Characteristic: Simple , all right preparatory cut of the craft , connecting fast, concentricity is good, have pattern person who restrain from advantage reinforcing bar carbon content.Applicable scope : Suitable for the concrete structure of the industry , civil buil ding and general structures, reinforcing bar diameter is for Фfor the the 16- 40mm one Ⅱ, Ⅲgrade verticality, it is the oblique to or reinforcing bars horizontal join construct live.conclusionsThese are now commonly used to connect steel synthesis methods, which links technology in the United States, Britain, Japan and other countries are widely used. There are different ways to connect their different characteristics and scope of the actual construction of production depending on the specific project choose a suitable method of connecting to achieve both energy conservation and saving time limit for a project ends.钢筋混凝土构造中钢筋连接综述改革开放以来，伴随国民经济旳迅速、持久发展，多种钢筋混凝土建筑构造大量建造，钢筋连接技术得到很大旳发展。
土木工程类外文文献翻译---钢筋混凝土可编辑
土木工程类外文文献翻译---钢筋混凝土外文文献翻译院系_________________________班级_________________________姓名_________________________指导教师_________________________2012年2月20 日2 外文翻译21 Reinforced ConcretePlain concrete is formed from a hardened mixture of cement water fine aggregate coarse aggregate crushed stone or gravel air and often other admixtures The plastic mix is placed and consolidated in the formwork then cured to facilitate the acceleration of the chemical hydration reaction lf the cementwater mix resulting in hardened concrete The finished product has high compressive strength and low resistance to tension such that its tensile strength is approximately one tenth lf its compressive strength Consequently tensile and shear reinforcement in the tensile regions of sections has to be provided to compensate for the weak tension regions in the reinforced concrete elementIt is this deviation in the composition of a reinforces concrete section from the homogeneity of standard wood or steel sections that requires a modified approach to the basic principles of structural design The two components of the heterogeneous reinforced concrete section are to be so arranged and proportioned that optimal use is made of the materials involved This is possible because concrete can easily be givenany desired shape by placing and compacting the wet mixture of the constituent ingredients are properly proportioned the finished product becomes strong durable and in combination with the reinforcing bars adaptable for use as main members of any structural system The techniques necessary for placing concrete depend on the type of member to be cast that is whether it is a column a bean a wall a slab a foundation a mass columns or an extension of previously placed and hardened concrete For beams columns and walls the forms should be well oiled after cleaning them and the reinforcement should be cleared of rust and other harmful materials In foundations the earth should be compacted and thoroughly moistened to about 6 in in depth to avoid absorption of the moisture present in the wet concrete Concrete should always be placed in horizontal layers which are compacted by means of high frequency power-driven vibrators of either the immersion or external type as the case requires unless it is placed by pumping It must be kept in mind however that over vibration can be harmful since it could cause segregation of the aggregate and bleeding of the concreteHydration of the cement takes place in the presence of moisture at temperatures above 50°F It is necessary to maintain such a condition in order that the chemical hydration reaction can take place If drying is too rapid surface cracking takes place This would result in reduction of concrete strength due to cracking as well as the failure to attain full chemical hydrationIt is clear that a large number of parameters have to be dealt with in proportioning a reinforced concrete element such as geometrical widthdepth area of reinforcement steel strain concrete strain steel stress and so on Consequently trial and adjustment is necessary in the choice of concrete sections with assumptions based on conditions at site availability of the constituent materials particular demands of the owners architectural and headroom requirements the applicable codes and environmental reinforced concrete is often a site-constructed composite in contrast to the standard mill-fabricated beam and column sections in steel structuresA trial section has to be chosen for each critical location in a structural system The trial section has to be analyzed to determine if its nominal resisting strength is adequate to carry the applied factored load Since more than one trial is often necessary to arrive at the required section the first design input step generates into a series of trial-and-adjustment analysesThe trial-and –adjustment procedures for the choice of a concrete section lead to the convergence of analysis and design Hence every design is an analysis once a trial section is chosen The availability of handbooks charts and personal computers and programs supports this approach as a more efficient compact and speedy instructional method compared with the traditional approach of treating the analysis of reinforced concrete separately from pure design22 EarthworkBecause earthmoving methods and costs change more quickly than those in any other branch of civil engineering this is a field where there are real opportunities for the enthusiast In 1935 most of the methods now inuse for carrying and excavating earth with rubber-tyred equipment did not exist Most earth was moved by narrow rail track now relatively rare and the main methods of excavation with face shovel backacter or dragline or grab though they are still widely used are only a few of the many current methods To keep his knowledge of earthmoving equipment up to date an engineer must therefore spend tine studying modern machines Generally the only reliable up-to-date information on excavators loaders and transport is obtainable from the makersEarthworks or earthmoving means cutting into ground where its surface is too high cuts and dumping the earth in other places where the surface is too low fills Toreduce earthwork costs the volume of the fills should be equal to the volume of the cuts and wherever possible the cuts should be placednear to fills of equal volume so as to reduce transport and double handlingof the fill This work of earthwork design falls on the engineer who lays out the road since it is the layout of the earthwork more than anything else which decides its cheapness From the available maps ahd levels the engineering must try to reach as many decisions as possible in the drawing office by drawing cross sections of the earthwork On the site when further information becomes available he can make changes in jis sections and layoutbut the drawing lffice work will not have been lost It will have helped him to reach the best solution in the shortest timeThe cheapest way of moving earth is to take it directly out of the cut and drop it as fill with the same machine This is not always possible but when it canbe done it is ideal being both quick and cheap Draglinesbulldozers and face shovels an do this The largest radius is obtained with the draglineand the largest tonnage of earth is moved by the bulldozer though only over short distancesThe disadvantages of the dragline are that it must dig below itself it cannot dig with force into compacted material it cannot dig on steep slopws and its dumping and digging are not accurate Face shovels are between bulldozers and draglines having a larger radius of action than bulldozers but less than draglines They are anle to dig into a vertical cliff face in a way which would be dangerous tor a bulldozer operator and impossible for a dragline Each piece of equipment should be level of their tracks and for deep digs in compact material a backacter is most useful but its dumping radius is considerably less than that of the same escavator fitted with a face shovelRubber-tyred bowl scrapers are indispensable for fairly level digging where the distance of transport is too much tor a dragline or face shovel They can dig the material deeply but only below themselves to a fairly flat surface carry it hundreds of meters if need be then drop it and level it roughly during the dumping For hard digging it is often found economical to keep a pusher tractor wheeled or tracked on the digging site to push each scraper as it returns to dig As soon as the scraper is fullthe pusher tractor returns to the beginning of the dig to heop to help the nest scraperBowl scrapers are often extremely powerful machinesmany makers build scrapers of 8 cubic meters struck capacity which carry 10 m 3 heaped The largest self-propelled scrapers are of 19 m 3 struck capacity 25 m 3 heaped and they are driven by a tractor engine of 430 horse-powersDumpers are probably the commonest rubber-tyred transport since they can also conveniently be used for carrying concrete or other building materials Dumpers have the earth container over the front axle on large rubber-tyred wheels and the container tips forwards on most types though in articulated dumpers the direction of tip can be widely varied The smallest dumpers have a capacity of about 05 m 3 and the largest standard types are of about 45 m 3 Special types include the self-loading dumper of up to 4 m 3 and the articulated type of about 05 m 3 The distinction between dumpers and dump trucks must be remembered dumpers tip forwards and the driver sits behind the load Dump trucks are heavy strengthened tipping lorries the driver travels in front lf the load and the load is dumped behind him so they are sometimes called rear-dump trucks23 Safety of StructuresThe principal scope of specifications is to provide general principles and computational methods in order to verify safety of structures The safety factor which according to modern trends is independent of the nature and combination of the materials used can usually be defined as the ratio between the conditions This ratio is also proportional to the inverse of the probability risk of failure of the structureFailure has to be considered not only as overall collapse of the structure but also as unserviceability or according to a more precise Common definition As the reaching of a limit state which causes the construction not to accomplish the task it was designed for There are two categories of limit state1 Ultimate limit sate which corresponds to the highest value of the load-bearing capacity Examples include local buckling or global instability of the structure failure of some sections and subsequent transformation of the structure into a mechanism failure by fatigue elastic or plastic deformation or creep that cause a substantial change of the geometry of the structure and sensitivity of the structure to alternating loads to fire and to explosions2 Service limit states which are functions of the use and durability of the structure Examples include excessive deformations and displacements without instability early or excessive cracks large vibrations and corrosionComputational methods used to verify structures with respect to the different safety conditions can be separated into1 Deterministic methods in which the main parameters are considered as nonrandom parameters2 Probabilistic methods in which the main parameters are considered as random parametersAlternatively with respect to the different use of factors of safety computational methods can be separated into1 Allowable stress method in which the stresses computed under imum loads are compared with the strength of the material reduced by given safety factors2 Limit states method in which the structure may be proportioned on the basis of its imum strength This strength as determined by rational analysis shall not be less than that required to support a factored loadequal to the sum of the factored live load and dead load ultimate state The stresses corresponding to working service conditions with unfactored live and dead loads are compared with prescribed values service limit state From the four possible combinations of the first two and second two methods we can obtain some useful computational methods Generally two combinations prevail1 deterministic methods which make use of allowable stresses2 Probabilistic methods which make use of limit statesThe main advantage of probabilistic approaches is that at least in theory it is possible to scientifically take into account all random factors of safety which are then combined to define the safety factor probabilistic approaches depend upon1 Random distribution of strength of materials with respect to the conditions of fabrication and erection scatter of the values of mechanical properties through out the structure2 Uncertainty of the geometry of the cross-section sand of the structure faults and imperfections due to fabrication and erection of the structure3 Uncertainty of the predicted live loads and dead loads acting on the structure4 Uncertainty related to the approximation of the computational method used deviation of the actual stresses from computed stresses Furthermore probabilistic theories mean that the allowable risk can be based on several factors such as1 Importance of the construction and gravity of the damage byits failure2 Number of human lives which can be threatened by this failure3 Possibility andor likelihood of repairing the structure4 Predicted life of the structureAll these factors are related to economic and social considerations such as1 Initial cost of the construction2 Aortization funds for the duration of the construction3 Cost of physical and material damage due to the failure of the construction4 Adverse impact on society5 Moral and psychological viewsThe definition of all these parameters for a given safety factor allows construction at the optimum cost However the difficulty of carrying out a complete probabilistic analysis has to be taken into account For such an analysis the laws of the distribution of the live load and its induced stresses of the scatter of mechanical properties of materials and of the geometry of the cross-sections and the structure have to be known Furthermore it is difficult to interpret the interaction between the law of distribution of strength and that of stresses because both depend upon the nature of the material on the cross-sections and upon the load acting on the structure These practical difficulties can be overcome in two ways The first is to apply different safety factors to the material and to the loads without necessarily adopting the probabilistic criterion The second is an approximate probabilistic method which introduces some simplifyingassumptions semi-probabilistic methods1 中文翻译11钢筋混凝土素混凝土是由水泥水细骨料粗骨料碎石或卵石空气通常还有其他外加剂等经过凝固硬化而成将可塑的混凝土拌合物注入到模板内并将其捣实然后进行养护以加速水泥与水的水化反应最后获得硬化的混凝土其最终制成品具有较高的抗压强度和较低的抗拉强度其抗拉强度约为抗压强度的十分之一因此截面的受拉区必须配置抗拉钢筋和抗剪钢筋以增加钢筋混凝土构件中较弱的受拉区的强度由于钢筋混凝土截面在均质性上与标准的木材或钢的截面存在着差异因此需要对结构设计的基本原理进行修改将钢筋混凝土这种非均质截面的两种组成部分按一定比例适当布置可以最好的利用这两种材料这一要求是可以达到的因混凝土由配料搅拌成湿拌合物经过振捣并凝固硬化可以做成任何一种需要的形状如果拌制混凝土的各种材料配合比恰当则混凝土制成品的强度较高经久耐用配置钢筋后可以作为任何结构体系的主要构件浇筑混凝土所需要的技术取决于即将浇筑的构件类型诸如柱梁墙板基础大体积混凝土水坝或者继续延长已浇筑完毕并且已经凝固的混凝土等对于梁柱墙等构件当模板清理干净后应该在其上涂油钢筋表面的锈及其他有害物质也应该被清除干净浇筑基础前应将坑底土夯实并用水浸湿6英寸以免土壤从新浇的混凝土中吸收水分一般情况下除使用混凝土泵浇筑外混凝土都应在水平方向分层浇筑并使用插入式或表面式高频电动振捣器捣实必须记住过分的振捣将导致骨料离析和混凝土泌浆等现象因而是有害的水泥的水化作用发生在有水分存在而且气温在50°F以上的条件下为了保证水泥的水化作用得以进行必须具备上述条件如果干燥过快则会出现表面裂缝这将有损与混凝土的强度同时也会影响到水泥水化作用的充分进行设计钢筋混凝土构件时显然需要处理大量的参数诸如宽度高度等几何尺寸配筋的面积钢筋的应变和混凝土的应变钢筋的应力等等因此在选择混凝土截面时需要进行试算并作调整根据施工现场条件混凝土原材料的供应情况业主提出的特殊要求对建筑和净空高度的要求所用的设计规范以及建筑物周围环境条件等最后确定截面钢筋混凝土通常是现场浇注的合成材料它与在工厂中制造的标准的钢结构梁柱等不同因此对于上面所提到的一系列因素必须予以考虑对结构体系的各个部位均需选定试算截面并进行验算以确定该截面的名义强度是否足以承受所作用的计算荷载由于经常需要进行多次试算才能求出所需的截面因此设计时第一次采用的数值将导致一系列的试算与调整工作选择混凝土截面时采用试算与调整过程可以使复核与设计结合在一起因此当试算截面选定后每次设计都是对截面进行复核手册图表和微型计算机以及专用程序的使用使这种设计方法更为简捷有效而传统的方法则是把钢筋混凝土的复核与单纯的设计分别进行处理12土方工程由于和土木工程中任何其他工种的施工方法与费用相比较土方挖运的施工方法与费用的变化都要快得多因此对于有事业心的人来说土方工程是一个可以大有作为的领域在1935年目前采用的利用轮胎式机械设备进行土方挖运的方法大多数还没有出现那是大部分土方是采用窄轨铁路运输在这目前来说是很少采用的当时主要的开挖方式是使用正铲反铲拉铲或抓斗等挖土机尽管这些机械目前仍然在广泛应用但是它们只不过是目前所采用的许多方法中的一小部分因此一个工程师为了使自己在土方挖运设备方面的知识跟得上时代的发展他应当花费一些时间去研究现代的机械一般说来有关挖土机装载机和运输机械的唯一可靠而又最新的资料可以从制造厂商处获得土方工程或土方挖运工程指的是把地表面过高处的土壤挖去挖方并把它倾卸到地表面过低的其他地方填方为了降低土方工程费用填方量应该等于挖方量而且挖方地点应该尽可能靠近土方量相等的填方地点以减少运输量和填方的二次搬运土方设计这项工作落到了从事道路设计的工程师的身上因为土方工程的设计比其他任何工作更能决定工程造价是否低廉根据现有的地图和标高道路工程师应在设计绘图室中的工作也并不是徒劳的它将帮助他在最短的时间内获得最好的方案费用最低的运土方法是用同一台机械直接挖方取土并且卸土作为填方这并不是经常可以做到的但是如果能够做到则是很理想的因为这样做既快捷又省钱拉铲挖土机推土机和正铲挖土机都能做到这点拉铲挖土机的工作半径最大推土机所推运的图的数量最多只是运输距离很短拉铲挖土机的缺点是只能挖比它本身低的土不能施加压力挖入压实的土壤内不能在陡坡上挖土而且挖卸都不准确正铲挖土机介于推土机和拉铲挖土机的之间其作用半径大于推土机但小于拉铲挖土机正铲挖土机能挖取竖直陡峭的工作面这种方式对推土机司机来说是危险的而对拉铲挖土机则是不可能的每种机械设备应该进行最适合它的性能的作业正铲挖土机不能挖比其停机平面低很多的土而深挖坚实的土壤时反铲挖土机最适用但其卸料半径比起装有正铲的同一挖土机的卸料半径则要小很多在比较平坦的场地开挖如果用拉铲或正铲挖土机运输距离太远时则装有轮胎式的斗式铲运机就是比不可少的它能在比较平的地面上挖较深的土但只能挖机械本身下面的土需要时可以将土运至几百米远然后卸土并在卸土的过程中把土大致铲平在挖掘硬土时人们发现在开挖场地经常用一辆助推拖拉机轮式或履带式对返回挖土的铲运机进行助推这种施工方法是经济的一旦铲运机装满助推拖拉机就回到开挖的地点去帮助下一台铲运机斗式铲运机通常是功率非常大的机械许多厂家制造的铲运机铲斗容量为8 m3满载时可达10 m3最大的自行式铲运机铲斗容量为19立方米满载时为25 m3由430马力的牵引发动机驱动翻斗机可能是使用最为普遍的轮胎式运输设备因为它们还可以被用来送混凝土或者其他建筑材料翻斗车的车斗位于大橡胶轮胎车轮前轴的上方尽管铰接式翻斗车的卸料方向有很多种但大多数车斗是向前翻转的最小的翻斗车的容量大约为05立方米而最大的标准型翻斗车的容量大约为45m3特殊型式的翻斗车包括容量为4 m3的自装式翻斗车和容量约为05 m3的铰接式翻斗车必须记住翻斗车与自卸卡车之间的区别翻斗车车斗向前倾翻而司机坐在后方卸载因此有时被称为后卸卡车13结构的安全度规范的主要目的是提供一般性的设计原理和计算方法以便验算结构的安全度就目前的趋势而言安全系数与所使用的材料性质及其组织情况无关通常把它定义为发生破坏的条件与结构可预料的最不利的工作条件之比值这个比值还与结构的破坏概率危险率成反比破坏不仅仅指结构的整体破坏而且还指结构不能正常的使用或者用更为确切的话来说把破坏看成是结构已经达到不能继续承担其设计荷载的极限状态通常有两种类型的极限状态即1强度极限状态它相当于结构能够达到的最大承载能力其例子包括结构的局部屈曲和整体不稳定性某此界面失效随后结构转变为机构疲劳破坏引起结构几何形状显著变化的弹性变形或塑性变形或徐变结构对交变荷载火灾和爆炸的敏感性2使用极限状态它对应着结构的使用功能和耐久性器例子包括结构失稳之前的过大变形和位移早期开裂或过大的裂缝较大的振动和腐蚀根据不同的安全度条件可以把结构验算所采用的计算方法分成1确定性的方法在这种方法中把主要参数看作非随机参数2概率方法在这种方法中主要参数被认为是随机参数此外根据安全系数的不同用途可以把结构的计算方法分为1容许应力法在这种方法中把结构承受最大荷载时计算得到的应力与经过按规定的安全系数进行折减后的材料强度作比较2极限状态法在这种方法中结构的工作状态是以其最大强度为依据来衡量的由理论分析确定的这一最大强度应不小于结构承受计算荷载所算得的强度极限状态计算荷载等于分别乘以荷载系数的活载与恒载之和把对应于不乘以荷载系数的活载和恒载的工作使用条件的应力与规定值使用极限状态相比较根据前两种方法和后两种方法的四种可能组合我们可以得到一些实用的计算方法通常采用下面两种计算方法确定性的方法这种方法采用容许应力概率方法这种方法采用极限状态至少在理论上概率法的主要优点是可以科学的考虑所有随机安全系数然后将这些随机安全系数组合成确定的安全系数概率法取决于1制作和安装过程中材料强度的随机分布整个结构的力学性能数值的分散性2截面和结构几何尺寸的不确定性由结构制作和安装造成的误差和缺陷而引起的对作用在结构上的活载和恒载的预测的不确定性所采用的近似计算方法有关的不精确性实际应力与计算应力的偏差此外概率理论意味着可以基于下面几个因素来确定允许的危险率例如建筑物的重要性和建筑物破坏造成的危害性2由于建筑物破坏使生活受到威胁的人数3修复建筑的可能性4建筑物的预期寿命所有这些因素均与经济和社会条件有关例如1建筑物的初始建设费2建筑物使用期限内的折旧费3由于建筑物破坏而造成的物质和材料损失费4在社会上造成的不良影响5精神和心理上的考虑就给定的安全系数而论所有这些参数的确定都是以建筑物的最佳成本为依据的但是应该考虑到进行全概率分析的困难对于这种分析来说应该了解活载及其所引起的盈利的分布规律材料的力学性能的分散性和截面的结构几何尺寸的分散性此外由于强度的分布规律和应力的分布规律之间的相互关系是困难的这些实际困难可以采用两种方法来克服第一种方法对材料和荷载采用不同的安全系数而不需要采用概率准则第二种方法是引入一些而简化假设的近似概率方法半概率方法1建筑工程学院土木工程系土木084班。
土建专业外文翻译---混凝土结构配筋设计
Concrete structure reinforcement designSheyanboⅠWangchenjiaⅡⅠ Foundation Engineering Co., Ltd. Heilongjiang Dongyu Ⅱ Heilongjiang Province, East Building FoundationEngineering Co., Ltd. Coal混凝土结构配筋设计佘艳波Ⅰ王晨佳ⅡⅠ基础工程有限公司黑龙江东宇Ⅱ黑龙江省东建筑地基基础工程有限公司煤摘要在长期的自然的环境下使用环境的功能结构，其功能减弱不可避免地渐渐地，我们的结构工程的责任不只是必须完成建设前期项目工作，但必须能够科学评价结构的破坏目标法律和程度，并采用有效的方法保证结构的安全使用，该结构加固将成为一个重要的工作。
什么可以预见将是21世纪，人类建筑的混凝土结构，钢结构，砌体式结构等为主另外，现阶段我会觉得在结构加固我们这方面的研究也应借此作为主要的突破方向。
关键词：混凝土结构加固砌体式结构钢筋结构加固1混凝土结构加固混凝土结构的加固分为直接加固，并加强间接两种，在设计时可根据实际条件和使用要求选择适宜的方法和必要的技术。
1.1直接加固的一般方法1.1.1放大段加固法添加混凝土现浇钢筋发生水平弯曲受压区混凝土构件，可能会增加部分有效高度，扩大截面面积，从而提高了组件的右侧部分反弯，斜截面抗切割能力部分刚度，起到加固补强的作用。
在适当的肌肉范围，改变混凝土弯曲的组件的右侧部分配套能力，随着钢筋面积和强度的提高增加。
在原来的组件的右侧部分钢筋的比例不太高的情况，增加了主要加固面积有可能提出的高原组件的右侧部分抗弯曲能力，有效地支持。
拉一节中，通过新的加拿大部分和原构件共同工作的领域添加现浇现浇混凝土外套组成部分增加，但提高了有效成分的配套能力，改善正常的经营业绩。
放大段加固法施工工艺简单，兼容，并具有成熟的设计和施工经验，在梁，板，柱，墙和一般结构用混凝土加固;但现场施工的湿作业时间长，对生产与生活有一定的影响，并加强建筑清拆后有一定减少。
混凝土毕业设计论文中英文对照资料外文翻译文献
外文文献及译文目录•1历史•2组成o水泥2.1o 2.2水o 2.3骨料o 2.4化学外加剂o 2.5掺合料和水泥混合o 2.6纤维•3搅拌混凝土•4个特点o 4.1和易o 4.2固化o 4.3强度o 4.4弹性o 4.5扩张和收缩o 4.6开裂▪ 4.6.1收缩裂缝▪ 4.6.2拉裂o 4.7蠕变•5损伤模式o 5.1火灾o 5.2总量扩张o 5.3海水效果o 5.4细菌腐蚀o 5.5化学武器袭击▪ 5.5.1碳化▪ 5.5.2氯化物▪ 5.5.3硫酸盐o 5.6浸出o 5.7人身损害•6种混凝土o 6.1普通混凝土o 6.2高强混凝土o 6.3高性能混凝土o 6.4自密实混凝土o 6.5喷浆o 6.6透水性混凝土o 6.7混凝土蜂窝o 6.8软木复合水泥o 6.9碾压混凝土o 6.10玻璃混凝土o 6.11沥青混凝土•7混凝土测试•8混凝土回收•9使用混凝土结构o9.1大体积混凝土结构o9.2钢筋混凝土结构o9.3预应力混凝土结构•10参见•11参考•12外部链接历史在塞尔维亚,仍然是一个小屋追溯到5600bce已经发现,同一个楼层发红色石灰,沙子和砾石。
金字塔陕西中建千多年前,含有石灰和火山灰.或粘土。
碎石水和泥浆僵硬和发展实力超过时间。
为了确保经济实用的解决方案,既罚款又粗骨料使用,以弥补大部分的混凝土混合物。
砂,天然砾石及碎石,主要用于这一目的。
不过,现在越来越普遍,再生骨料(由建筑,拆卸和挖掘废物)被用作局部代替天然骨料,而一些生产总量包括风冷高炉炉渣和粉煤灰也是不允许的。
装饰石材等石英岩,潆石块或玻璃破碎,有时添加到混凝土表面进行装饰性"的总暴露"完成,流行景观设计师。
化学外加剂化学外加剂现形式的材料粉末或液体,补充了混凝土给它的某些特性没有可与普通混凝土混合物。
在正常情况下使用,外加剂剂量均低于5%的大量水泥,并补充了混凝土当时的配料/混合.最常见的外加剂有:加速器加速水化(硬化)的混凝土。
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(文档含英文原文和中文翻译)中英文对照外文翻译英文原文：Concrete structure reinforcement designAbstract：structure in the long-term natural environment and under the use environment's function, its function is weaken inevitably gradually, our structural engineering's duty not just must finish the building earlier period the project work, but must be able the science appraisal structure damage objective law and the degree, and adopts the effective method guarantee structure the security use, that the structure reinforcement will become an important work. What may foresee will be the 21st century, the human building also by the concrete structure, the steel structure, the bricking-up structure and so on primarily, the present stage I will think us in the structure reinforcement this aspect research should also take this as themain breakthrough direction.Key word： Concrete structure reinforcement bricking-up structure reinforcement steel structure reinforcement1 Concrete structure reinforcementConcrete structure's reinforcement divides into the direct reinforcement and reinforces two kinds indirectly, when the design may act according to the actual condition and the operation requirements choice being suitable method and the necessary technology.1.1the direct reinforcement's general method1）Enlarges the section reinforcement lawAdds the concretes cast-in-place level in the reinforced concrete member in bending compression zone, may increase the section effective height, the expansion cross sectional area, thus enhances the component right section anti-curved, the oblique section anti-cuts ability and the section rigidity, plays the reinforcement reinforcement the role.In the suitable muscle scope, the concretes change curved the component right section supporting capacity increase along with the area of reinforcement and the intensity enhance. In the original component right section ratio of reinforcement nottoo high situation, increases the main reinforcement area to be possible to propose the plateau component right section anti-curved supporting capacity effectively. Is pulledin the section the area to add the cast-in-place concrete jacket to increase the component section, through new Canada partial and original component joint work,but enhances the component supporting capacity effectively, improvement normal operational performance.Enlarges the section reinforcement law construction craft simply, compatible,and has the mature design and the construction experience; Is suitable in Liang, the board, the column, the wall and the general structure concretes reinforcement; But scene construction's wet operating time is long, to produces has certain influence withthe life, and after reinforcing the building clearance has certain reduction.2) Replacement concretes reinforcement lawThis law's merit with enlarges the method of sections to be close, and afterreinforcing, does not affect building's clearance, but similar existence construction wet operating time long shortcoming; Is suitable somewhat low or has concretes carrier's and so on serious defect Liang, column in the compression zone concretes intensity reinforcement.3) the caking outsourcing section reinforcement lawOutside the Baotou Steel Factory reinforcement is wraps in the section or the steel plate is reinforced component's outside, outside the Baotou Steel Factory reinforces reinforced concrete Liang to use the wet outsourcing law generally, namely uses the epoxy resinification to be in the milk and so on methods with to reinforce the section the construction commission to cake a whole, after the reinforcement component, because is pulled with the compressed steel cross sectional area large scale enhancement, therefore right section supporting capacity and section rigidity large scale enhancement.This law also said that the wet outside Baotou Steel Factory reinforcement law, the stress is reliable, the construction is simple, the scene work load is small, but is big with the steel quantity, and uses in above not suitably 600C in the non-protection's situation the high temperature place; Is suitable does not allow in the use obviously to increase the original component section size, but requests to sharpen its bearing capacity large scale the concrete structure reinforcement.4) Sticks the steel reinforcement lawOutside the reinforced concrete member in bending sticks the steel reinforcement is (right section is pulled in the component supporting capacity insufficient sector area, right section compression zone or oblique section) the superficial glue steel plate, like this may enhance is reinforced component's supporting capacity, and constructs conveniently.This law construction is fast, the scene not wet work or only has the plastering and so on few wet works, to produces is small with the life influence, and after reinforcing, is not remarkable to the original structure outward appearance and the original clearance affects, but the reinforcement effect is decided to a great extent by the gummy craft and the operational level; Is suitable in the withstanding static function, and is in the normal humidity environment to bend or the tension memberreinforcement.5) Glue fibre reinforcement plastic reinforcement lawOutside pastes the textile fiber reinforcement is pastes with the cementing material the fibre reinforcement compound materials in is reinforced the component to pull the region, causes it with to reinforce the section joint work, achieves sharpens the component bearing capacity the goal. Besides has glues the steel plate similar merit, but also has anticorrosive muddy, bears moistly, does not increase the self-weight of structure nearly, durably, the maintenance cost low status merit, but needs special fire protection processing, is suitable in each kind of stress nature concrete structure component and the general construction.This law's good and bad points with enlarge the method of sections to be close; Is suitable reinforcement which is insufficient in the concrete structure component oblique section supporting capacity, or must exert the crosswise binding force to the compressional member the situation.6) Reeling lawThis law's good and bad points with enlarge the method of sections to be close; Is suitable reinforcement which is insufficient in the concrete structure component oblique section supporting capacity, or must exert the crosswise binding force to the compressional member the situation.7) Fang bolt anchor lawThis law is suitable in the concretes intensity rank is the C20~C60 concretes load-bearing member transformation, the reinforcement; It is not suitable for already the above structure which and the light quality structure makes decent seriously.1.2The indirect reinforcement's general method1)Pre-stressed reinforcement law(1)Thepre-stressed horizontal tension bar reinforces concretes member in bending,because the pre-stressed and increases the exterior load the combined action, in the tension bar has the axial tension, this strength eccentric transmits on the component through the pole end anchor (, when tension bar and Liang board bottom surface close fitting, tension bar can look for tune together with component, thisfashion has partial pressures to transmit directly for component bottom surface), has the eccentric compression function in the component, this function has overcome the bending moment which outside the part the load produces, reduced outside the load effect, thus sharpened component's anti-curved ability. At the same time, because the tension bar passes to component's pressure function, the component crack development can alleviate, the control, the oblique section anti-to cut the supporting capacity also along with it enhancement.As a result of the horizontal lifting stem's function, the original component's section stress characteristic by received bends turned the eccentric compression, therefore, after the reinforcement, component's supporting capacity was mainly decided in bends under the condition the original component's supporting capacity 。