毕业设计外文翻译

本科生毕业设计（论文）
外文翻译
（2018届）
译文及原稿
译文题目建筑材料
原稿题目Structural Materials
原稿出处Civil Engineering Materials、Shan Somayaji、美国、Pearson2000年、4页
2017年12月31日
译文
建筑材料
摘要：土木工程是个庞大的学科，但最主要的是建筑，建筑无论是在中国还是在国外，都有着悠久的历史，长期的发展历程。

整个世界每天都在改变，而建筑也随科学的进步而发展。

力学的发现，材料的更新，不断有更多的科学技术引入建筑中。

以前只求一间有瓦盖顶的房屋，现在追求舒适，不同的思想，不同的科学，推动了土木工程的发展，使其更加完美。

关键词：土木工程：建筑；力学；材料
混凝土与钢筋混凝土作为建筑材料在每个国家被使用着。

在很多国家，包括美国和加拿大，钢筋混凝土是建造的建筑物中主要的结构材料。

钢筋混凝土建筑物通用的特性归因于能大量得到钢筋和混凝土的组分（即碎石、砂和水泥），混凝土施工需要相对简单的技术，以及与其他形式的建筑相比钢筋混凝土的经济性。

混凝土与钢筋混凝土用于桥梁、各种房屋、地下结构、水箱、电视塔、近海石油开采和生产结构、大坝甚至船舶。

早期主要的建筑材料是木材和砌体，如砖、石、瓦以及类似的材料。

砖层之间通过砂浆、沥青（一种焦油状的物质）或其他一些粘合剂粘合在一起。

希腊人和罗马人有时用铁条或夹子来加固他们的房屋。

例如，雅典的帕台农神庙柱子中曾钻孔以便加入铁条，如今都已锈蚀殆尽。

罗马人也用称作白榴火山灰的天然水泥，它用火山灰制作，在水中会变得与石头一样坚硬。

作为现代两种最重要的建筑材料，钢材与水泥在十九世纪得到了推广。

直到那个时候，钢材才通过繁复的过程制造出来，基本上是铁合金，并含有少量的碳，因而被限制在一些特殊的用途如刀刃。

在1856年发明了贝塞麦炼钢法后，钢材才得以大量低价获得。

钢材巨大的优势即是它的抗拉强度，也就是当它在适当的拉力下不会失去强度，正如我们所看到的，该力往往能够将很多材料拉开。

新的合金进一步提高了钢材的强度，并消除了一些缺点，如疲劳，即在连续的应力变化下导致强度减弱的趋势。

现代水泥发明于1824年，称为波特兰水泥。

它是石灰石和粘土的混合物，加热后磨成粉末。

在或靠近施工现场，将水泥与砂、骨料（小石头、压碎的岩石或砾石）、水混合而制成混凝土。

不同比例的配料会制造出不同强度和重量的混凝土。

混凝土的用途很多，可以浇筑、泵送甚至喷射成各种形状。

混凝土具有很大的抗压强度，混凝土受压强、受拉弱。

因此，每当受荷、收缩受阻或温度变化引起的拉应力超过混凝土的抗拉强度时，便会发生开裂。

在素混凝土梁中，因外力引起的力矩由内部的拉-压形成的力偶来抵抗，此力偶中包含了混凝土的拉力。

当第一条裂缝形成时，此梁会突然、完全地失效。

在钢筋混凝土梁中，钢筋埋置在混凝土内的方式应能使混凝土开裂后在钢筋中产生平衡力矩所需的拉力。

而钢材具有很大的抗拉强度。

这样，两种材料可以互补。

水泥与钢筋混凝土的联合委员会于1904年建立，包括美国土木工程师协会、美国测试和材料协会、美国铁路工程协会和美国波特兰水泥制造协会。

该团体中
后来又加入了美国混凝土协会。

在1904-1910年间，联合委员会进行了研究。

在1913年发布的初步报告中列出了在1898-1911年间发表的关于钢筋混凝土的较重要的文件和书籍。

该委员会最后的报告发表于1916。

Kerekes and Reid在1954对钢筋混凝土建筑规范在美国的发展历史作了回顾。

它们也以另外一种方式互补：它们几乎有相同的收缩率和膨胀率。

因此，它们在拉、压为主要因素时能共同工作。

在出现拉力的混凝土梁或结构中，将钢筋埋入混凝土而成钢筋混凝土。

混凝土与钢筋形成如此强大的结合力——这个力将它们粘合在一起——以致于钢筋在混凝土中不会滑移。

还有另一个优势是钢筋在混凝土中不会锈蚀。

酸能腐蚀钢筋，而混凝土会发生碱性的化学反应，与酸相反。

结构钢与钢筋混凝土的采用使传统的施工作业发生了明显的变化。

对多层建筑，再也没必要采用厚的石墙或砖墙，且施工防火地面变为容易得多。

这些变化有利于降低建筑的成本。

它也使建造高度更高和跨度更大的建筑物成为可能。

由于现代结构的重量由钢或混凝土框架承受，墙体不再支承建筑物。

它们成为幕墙，将日晒风吹雨打阻挡在外，而让光线进入。

在较早的钢或混凝土框架建筑中，幕墙一般由砌体构成；它们具有承重墙的结实外观。

但是今天，幕墙通常由轻质材料组成，如玻璃、铝或塑料，并形成不同的组合。

钢结构中的另一个进步是梁的连接方式。

在很多年里，连接的标准方式是铆接。

铆钉是个有头的螺栓，看上去象个没有螺纹的圆头螺丝钉。

铆钉加热后穿过钢构件之间的孔洞，并通过锤击另一端而形成第二个铆钉头，从而将其固定就位。

如今铆接已大量地被焊接所替代，钢构件间的连接通过在高热下熔化它们之间的钢材料（即焊条）进行。

材料对建筑和结构功能的适应性：钢筋混凝土系统常常允许设计者将建筑和结构的功能结合起来。

混凝土的优势是能以塑性的状态放置，并通过模板和加工技术给出需要的形状和密度。

当楼面和顶棚面完成时，允许这些构件诸如平面板或其他类型的板充当受力构件。

类似地，钢筋混凝土墙除了能抵抗重力、风或地震荷载外，还能提供建筑上吸引人的外观。

最后，尺寸和形状的选择由设计者来决定，而不是由标准制造构件的可得性来决定。

预应力混凝土是加强法的改进形式。

将钢筋弯成一定的形状以使它们具有必要的抗拉强度，然后用该钢筋对混凝土施加预应力，通常可采用两种不同方法中的任何一种。

第一种方法是在混凝土梁中按钢筋的形状留下孔道，当钢筋穿过孔道后，通过在孔道内灌注薄砂浆（一种稀薄的砂浆或粘合剂）将钢筋与混凝土粘结在一起。

另一种（更常用的）方法是将预应力钢筋置于按成品结构的形状设置的模板的较低部位，然后将混凝土倒入（模板）而包围着钢筋。

预应力混凝土使用了较少的钢筋和混凝土，由于它是如此的经济，因此是一种非常理想的材料。

预应力混凝土使建造独特形状的建筑物成为可能，象一些现代的运动场，它具有不受任何支撑物阻挡视线的大空间。

这种较新的结构方法的使用正在不断地被扩大。

目前的趋势是采用较轻的材料。

例如，铝的重量比钢轻得多，但具有很多相同的性能。

铝材梁已经用于桥梁建筑和一些建筑的框架。

另一个例子是轻质混凝土，如今已在全世界快速地发展，因它们的绝热性而被采用，其三种类型举例说明如下：(a)轻质骨料制成的混凝土；(b)通过浇筑时搅拌或一些化学方法起泡而成的加气混凝土（US加气混凝土）；(c)无细骨料混凝土。

这三种类型的混凝土都是由于它们的绝热性而被使用，主要用于房屋，使其
在寒冷的气候中非常舒服，在炎热的气候中降温的成本不高。

在房屋中，墙采用较薄弱的轻质混凝土不重要，但是屋面板、楼面板和梁（采用轻质混凝土）则有重大关系。

在某些地区，一些轻质骨料的费用几乎等于最致密的骨料，因此大量的楼面板采用轻骨料混凝土制作纯粹是节约重量，而没考虑它的绝热价值。

轻质骨料使楼面的恒载减少了约20%，因而大量的节约了每层楼面以及屋面的楼盖结构中的钢材和柱子与基础中（较少）的钢材使用量。

一位伦敦的承包商宁愿使用轻质骨料，因为这使楼面板上减少的重量与用空心砖相同，且组织更简单，因而速度和利润更高。

轻质骨料的绝热价值只在屋面绝热时显得重要，它已被大大地改进了。

材料的可得性:砂、碎石（砾石）、水泥以及混凝土的搅拌设施可以非常广泛的得到，且钢筋比结构钢更容易地运至多数施工现场。

因此，钢筋混凝土经常用在偏远的区域。

另一方面，有许多因素可能导致一个人选择的材料不是钢筋混凝土。

这包括：低的抗拉强度。

正如前面所述的，混凝土的抗拉强度比它的抗压强度要低得多（约1/10），因而混凝土易遭受开裂。

在结构使用中，通过采用钢筋承受拉力，并限制裂缝宽度在可接受的数值内来克服这一点。

但是，除非在设计与施工中小心谨慎，否则这些裂缝可能会难看或使水渗透。

经济性:最重要的考虑常常是该结构的总费用。

当然，这是一个建造结构而必需的材料和劳动力费用的函数。

但是，总费用经常同样地或更多地受总的建造时间的影响，因为承包商和业主必须分配资金来进行建造，并直到建筑物可以使用才能收回投资。

因快速施工而使财务的节约可足以抵消增加的材料费用。

设计者为使设计和加工标准化所采取的任何措施通常都将在降低的总费用中得益。

原文
Structural Materials
Abstract:the civil engineering is a huge discipline,but the main one is building,building wh ether in China or abroad,has a long history,long-term development process.The world is changin g every day,but the building also along with the progress of science and development.Mechanics findings,material of update,ever more scientific technology into the building.But before a room with a tile to cover the top of the house,now for comfort,different ideas,different scientific,prom oted the development of civil engineering,making it more perfect.
key words:civil engineering;Architecture;Mechanics,Materials.
Concrete and reinforced concrete are used as building materials in every country.In many,i ncluding the United States and Canada,reinforced concrete is a dominant structural material in en gineered construction.The universal nature of reinforced concrete construction stems from the w ide availability of reinforcing bars and the constituents of concrete,gravel,sand,and cement,the r elatively simple skills required in concrete construction,and the economy of reinforced concrete c ompared to other form of construction.Concrete and reinforced concrete are used in bridges,build ings of all sorts,underground structures,water tanks,television towers,offshore oil exploration an d production structures,dams,and even in ships.
The principal construction materials of earlier times were wood and masonry-brick,stone,o r tile,and similar materials.The courses or layers were bound together with mortar or bitumen,a t arlike substance,or some other binding agent.The Greeks and Romans sometimes used iron rod s or clamps to strengthen their building.The columns of the Parthenon in Athens,for example,ha ve holes drilled in them for iron bars that have now rusted away.The Romans also used a natura l cement called pozzolana,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,wer e introduced in the nineteenth century.Steel,basically an alloy of iron and a small amount of car bon,had been made up to that time by a laborious process that restricted it to such special uses a s sword blades.After the invention of the Bessemer process in1856,steel was available in large q uantities at low prices.The enormous advantage of steel is its tensile strength;that is,it does not lo se its strength when it is under a calculated degree of tension,a force which,as we have seen,ten ds to pull apart many materials.New alloys have further increased the strength of steel and elimin ated some of its problems,such as fatigue,which is a tendency for it to weaken as a result of conti nual changes in stress.
Modern cement,called Portland cement,was invented in1824.It is a mixture of limestone
and clay,which is heated and then ground into a powder.It is mixed at or near the construction si te with sand,aggregate small stones,crushed rock,or gravel),and water to make concrete.Differe nt proportions of the ingredients produce concrete with different strength and weight.Concrete i s very versatile;it can be poured,pumped,or even sprayed into all kinds of shapes.And whereas s teel has greattensile strength,concrete has great strength under compression.Concrete is strong i n compression but weak in tension.As a result,cracks develop wheneverloads,or restrained shrin kage or temperature changes,give rise to tensile stresses in excess of the tensile strength of the c oncrete.In the plain concrete beam,the moments due to applied loads are resisted by an internal t ension-compression couple involving tension in the concrete.Such a beam fails very suddenly an d completely when the first crack forms.In a reinforced concrete beam,steel bars are embedded i n the concrete in such a way that the tension forces needed for moment equilibrium after the concr ete cracks can be developed in the bars.Thus,the two substances complement each other.
A Joint Committee on Concrete and Reinforced Concrete was established in1904by th e American Society of Civil Engineers,American Society for Testing and Materials,the America n Railway Engineering Association,and the Association of American Portland Cement Manufactu res.This group was later joined by the American Concrete Institute.Between1904and1910the J oint Committee carried out research.A preliminary report issued in1913lists the more importan t papers and books on reinforced concrete published between1898and1911.The final report of t his committee was published in1916.The history of reinforced concrete building codes in the Uni ted States was reviewed in1954by Kerekes and Reid.
They also complement each other in another way:they have almost the same rate of contr action and expansion.They therefore can work together in situations where both compression an
d tension ar
e factors.Steel rods are embedded in concrete to make reinforced concrete in concret
e beams or structures where tension will develop.Concrete and steel also form such a strong bon d-the force that unites them-that the steel cannot slip with the concrete.Still another advantage i s that steel does not rust in concrete.Acid corrodes steel,whereas concrete has an alkaline chemic al reaction,the opposite o
f acid.
The adoption of structural steel and reinforced concrete caused major changes in traditiona l construction practices.It was no longer necessary to use thick walls of stone or brick for multisto ry buildings,and it became much simpler to build fire-resistant floors.Both these changes served t o reduce the cost of construction.It also became possible to erect buildings with greater heights a nd longer spans.
Since the weight of modern structures is carried by the steel or concrete frame,the walls d o not support the building.They have become curtain walls,which keep out the weather and let i
n light.In the earlier steel or concrete frame building,the curtain walls were generally made of ma sonry;they had the solid look of bearing walls.Today,however,curtain walls are often made of li ghtweight materials such as glass,aluminum,or plastic,in various combinations.
Suitability of Material for Architectural and Structural Function A reinforced conc rete system frequently allows the designer to combine the architectural and structural functions.C oncrete has the advantage that it is placed in a plastic condition and is given the desired shape an d texture by means of the forms and the finishing techniques.This allows such elements as flat pl ates or other types of slabs to serve as load-bearing elements while providing the finished floor an d ceiling surface.Similarly,reinforced concrete walls can provide architecturally attractive surface s in addition to having the ability to resist gravity,wind,or seismic loads.Finally,the choice of siz e or shape is governed by the designer and not by the availability of standard manufactured memb ers.
Another advance in steel construction is the method of fastening together the beams.For m any years the standard method wasriveting.A rivet is a bolt with a head that looks like a blunt scre w without threads.It is heated,placed in holes through the pieces of steel,and a second head is for med at the other end by hammering it to hold it in place.Riveting has now largely been replace d by welding,the joining together of pieces of steel by melting a steel material between them unde r high heat.
Prestressed concrete is an improved form of reinforcement.Steel rods are bent into the sha pes to give them the necessary degree of tensile strength.They are then used to prestress concret e,usually by one of two different methods.The first is to leave channels in a concrete beam that c orrespond to the shapes of the steel rods.When the rods are run through the channels,they are the n bonded to the concrete by filling the channels with grout,a thin mortar or binding agent.In the o ther(and more common)method,the prestressed steel rods are placed in the lower part of a for m that corresponds to the shape of the finished structure,and the concrete is poured around the m.Prestressed concrete uses less steel and less concrete.Because it is so economical,it is a highl y desirable material.
Prestressed concrete has made it possible to develop buildings with unusual shapes,like so me of the modern sports arenas,with large space unbroken by any obstructing supports.The uses f or this relatively new structural method are constantly being developed.
The current tendency is to develop lighter materials,aluminum,for example,weighs muc h less than steel but has many of the same properties.Aluminum beams have already been used fo r bridge construction and for the framework of a few buildings.
Lightweight concretes,another example,are now rapidly developing throughout the worl
d.They are used for their thermal insulation.The three types are illustrated below:(a)Concrete
s made with lightweight aggregates;(b)Aerated concretes(US gas concretes)foamed by whisking or by some chemical process during casting;(c)No-fines concretes.
All three types are used for their insulating properties,mainly in housing,where they giv e high comfort in cold climates and a low cost of cooling in hot climates.In housing,the relativ e weakness of lightweight concrete walls is unimportant,but it matters in roof slabs,floor slabs an d beams.
In some locations,some lightweight aggregates cost little more than the best dense aggr egates and a large number of floor slabs have therefore been built of lightweight aggregate concre te purely for its weight saving,with no thought of its insulation value.
The lightweight aggregate reduces the floor dead load by about20per cent resulting in co nsiderable savings in the floor steel in every floor and the roof,as well as in the column steel an d(less)in the foundations.One London contractor prefers to use lightweight aggregate because i t gives him the same weight reduction in the floor slab as the use of hollow tiles,with simpler orga nization and therefore higher speed and profit.The insulation value of the lightweight aggregate i s only important in the roof insulation,which is greatly improved.
Availability of Materials Sand,gravel,cement,and concrete mixing facilities are very w idely available,and reinforcing steel can be transported to most job sites more easily than can str uctural steel.As a result,reinforced concrete is frequently used in remote areas.On the other han d,there are a number of factors that may cause one to select a material other than reinforced concr ete.These include：Low Tensile Strength As stated earlier,the tensile strength of concrete is mu ch lower than its compressive strength(about1/10),and hence concrete is subject to cracking.I n structural uses this is overcome by using reinforcement to carry tensile forces and limit crack wi dths to within acceptable values.Unless care is taken in design and construction,however,these c racks may be unsightly or may allow penetration of water.
Economy Frequently,the foremost consideration is the overall cost of the structure.Thi s is,of course,a function of the costs of the materials and the labor necessary to erect them.Frequ ently,however,the overall cost is affected as much or more by the overall construction time sinc e the contractor and owner must allocate money to carry out the construction and will not receiv e a return on this investment until the building is ready for occupancy.As a result,financial saving s due to rapid construction may more than offset increased material costs.Any measures designe r can take to standardize the design and forming will generally pay off in reduced overall costs.。