The behavior of reinforced concrete columns subjected to axial

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外文翻译外文文献英文文献国际建设工程风险分析

外文文献：This analysis used a case study methodology to analyze the issues surrounding the partial collapse of the roof of a building housing the headquarters of the Standards Association of Zimbabwe (SAZ). In particular, it examined the prior roles played by the team of construction professionals. The analysis revealed that the SAZ’s traditional construction project was generally characterized by high risk. There was a clear indication of the failure of a contractor and architects in preventing and/or mitigating potential construction problems as alleged by the plaintiff. It was reasonable to conclude that between them the defects should have been detected earlier and rectified in good time before the partial roof failure. It appeared justified for the plaintiff to have brought a negligence claim against both the contractor and the architects. The risk analysis facilitated, through its multi-dimensional approach to a critical examination of a construction problem, the identification of an effective risk management strategy for future construction prject and riskThe structural design of the reinforced concrete elements was done by consulting engineers Knight Piesold (KP). Quantity surveying services were provided by Hawkins, Leshnick & Bath (HLB). The contract was awarded to Central African Building Corporation (CABCO) who was also responsible for the provision of a specialist roof structure using patented “gang nail” roof trusses. The building construction proceeded to completion and was handed over to the owners on Sept. 12, 1991. The SAZ took effective occupation of the headquarters building without a certificate of occupation. Also, the defects liability period was only three months .The roof structure was in place 10 years At first the SAZ decided to go to arbitration, but this failed to yield an immediate solution. The SAZ then decided toproceed to litigate in court and to bring a negligence claim against CABCO. The preparation for arbitration was reused for litigation. The SAZ’s quantified losses stood at approximately $ 6 million in Zimbabwe dollars (US $1.2m) .After all parties had examined the facts and evidence before them, it became clear that there was a great probability that the courts might rule that both the architects and the contractor were lia ble. It was at this stage that the defendants’ lawyers requested that the matter be settled out of court. The plaintiff agreed to this suxamined the prior roles played by the project management function and construction professionals in preventing/mitigating potential construction problems. It further assessed the extent to which the employer/client and parties to a construction contract are able to recover damages under that contract. The main objective of this critical analysis was to identify an effective risk management strategy for future construction projects. The importance of this study is its multidimensional examination approach.Experience sugge be misleading. All construction projects are prototypes to some extent and imply change. Change in the construction industry itself suggests that past experience is unlikely to be sufficient on its own. A structured approach is required. Such a structure can not and must not replace the experience and expertise of the participant. Rather, it brings additional benefits that assist to clarify objectives, identify the nature of the uncertainties, introduces effective communication systems, improves decision-making, introduces effective risk control measures, protects the project objectives and provides knowledge of the risk history .Construction professionals need to know how to balance the contingencies of risk with their specific contractual, financial, operational and organizational requirements. Many construction professionals look at risks in dividually with a myopic lens and donot realize the potential impact that other associated risks may have on their business operations. Using a holistic risk management approach will enable a firm to identify all of the organization’s business risks. This will increas e the probability of risk mitigation, with the ultimate goal of total risk elimination .Recommended key construction and risk management strategies for future construction projects have been considered and their explanation follows. J.W. Hinchey stated th at there is and can be no ‘best practice’ standard for risk allocation on a high-profile project or for that matter, any project. He said, instead, successful risk management is a mind-set and a process. According to Hinchey, the ideal mind-set is for the parties and their representatives to, first, be intentional about identifying project risks and then to proceed to develop a systematic and comprehensive process for avoiding, mitigat and its location. This is said to be necessary not only to allow alternative responses to be explored. But also to ensure that the right questions are asked and the major risks identified. Heads of sources of risk are said to be a convenient way of providing a structure for identifying risks to completion of a participant’s pa rt of the project. Effective risk management is said to require a multi-disciplinary approach. Inevitably risk management requires examination of engineering, legal and insurance related solutions .It is stated that the use of analytical techniques based on a statistical approach could be of enormous use in decision making . Many of these techniques are said to be relevant to estimation of the consequences of risk events, and not how allocation of risk is to be achieved. In addition, at the present stage of the development of risk management, Atkinson states that it must be recognized that major decisions will be made that can not be based solely on mathematical analysis. The complexity ofconstruction projects means that the project definition in terms of both physical form and organizational structure will be based on consideration of only a relatively small number of risks . This is said to then allow a general structured approach that can be applied to any construction project to increase the awareness of participants .The new, simplified Construction Design and Management Regulations (CDM Regulations) which came in to f 1996, into a single regulatory package.The new CDM regulations offer an opportunity for a step change in health and safety performance and are used to reemphasize the health, safety and broader business benefits of a well-managed and co-ordinated approach to the management of health and safety in construction. I believe that the development of these skills is imperative to provide the client with the most effective services available, delivering the best value project possible.Construction Management at Risk (CM at Risk), similar to established private sector methods of construction contracting, is gaining popularity in the public sector. It is a process that allows a client to select a construction manager (CM) based on qualifications; make the CM a member of a collaborative project team; centralize responsibility for construction under a single contract; obtain a bonded guaranteed maximum price; produce a more manageable, predictable project; save time and money; and reduce risk for the client, the architect and the CM.CM at Risk, a more professional approach to construction, is taking its place along with design-build, bridging and the more traditional process of design-bid-build as an established method of project delivery.The AE can review to get the projec. Competition in the community is more equitable: all subcontractors have a fair shot at the work .A contingency within the GMP covers unexpected but justifiable costs, and a contingency above the GMP allows for client changes. As long as the subcontractors are within the GMP they are reimbursed to the CM, so the CM represents the client in negotiating inevitable changes with subcontractors.There can be similar problems where each party in a project is separately insured. For this reason a move towards project insurance is recommended. The traditional approach reinforces adversarial attitudes, and even provides incentives for people to overlook or conceal risks in an attempt to avoid or transfer responsibility.A contingency within the GMP covers unexpected but justifiable costs, and a contingency above the GMP allows for client changes. As long as the subcontractors are within the GMP they are reimbursed to the CM, so the CM represents the client in negotiating inevitable changes with subcontractors.There can be similar problems where each party in a project is separately insured. For this reason a move towards project insurance is recommended. The traditional approach reinforces adversarial attitudes, and even provides incentives for people to overlook or conceal risks in an attempt to avoid or transfer responsibility.It was reasonable to assume that between them the defects should have been detected earlier and rectified in good time before the partial roof failure. It did appear justified for the plaintiff to have brought a negligence claim against both the contractor and the architects.In many projects clients do not understand the importance of their role in facilitating cooperation and coordination; the desi recompense. They do not want surprises, and are more likely to engage in litigation when things go wrong.中文译文：国际建设工程风险分析索赔看来是合乎情理的。

土木工程专业外语课文翻译

土木工程专业外语课文翻译专业英语课文翻译Lesson 4Phrases and Expressions1.moisture content 含水量，含湿度; water content 2.cement paste 水泥浆 mortar 3.capillary tension 毛细管张力，微张力 4.gradation of aggregate 骨料级配 coarse fine (crushed stone , gravel ) 5.The British Code PC 100 英国混凝土规范PC 100; nowaday BS 8110 6. coefficient of thermal expansion of concrete 混凝土热膨胀系数 7. The B .S Code 英国标准规范8. sustained load 永久荷载，长期荷载9. permanent plastic strain 永久的塑性应变stress 10. crystal lattice 晶格, 晶格11. cement gel 水泥凝胶体12. water -cement ratio 水灰比13. expansion joint 伸缩缝 14. stability of the structure 结构的稳定性structural stability 15. fatigue strength of concrete 混凝土的疲劳强度 Volume Changes of ConcreteConcrete undergoes volume changes during hardening . 混凝土在硬结过程中会经历体积变化。

If it loses moisture by evaporation , it shrinks , but if the concrete hardens in water , it expands . 如果蒸发失去水分，混凝土会收缩；但如果在水中硬结，它便膨胀。

专业英语翻译答案

混凝土随着龄期而逐渐硬化，当混凝土已经达到足够的强度后，水化的过程还会持续一段很长的时间。
CONTENT
Normal concrete has a comparatively low tensile strength and for structural applications it is normal practice either to incorporate steel bars to resist any tensile forces (steel reinforced concrete) or to apply compressive forces to the concrete to counteract these tensile forces (pre-stressed concrete or post-stressed concrete).
CONTENT
As an engineer, one must know about the materials used in the construction site.
作为一名工程人员必须知道施工现场所用的建筑材料。
It is necessary for an engineer to be conversant with the properties of such materials.
普通混凝土有相对较低的抗拉强度，对于结构应用来说，通常的做法是加入钢筋来抵抗拉力的作用（钢筋混凝土）或者是给混凝土施加压力的作用来抵消这些拉力（先张法预应力混凝土或后张法预应力混凝土）。
CONTENT
It is used also for a wide range of precast concrete products which include concrete blocks, cladding panels, and pipes.

The diagonal tension behavior of fiber reinforced concrete beams

The diagonal tension behavior of ﬁber reinforced concrete beamsCe´sar Jua ´rez *,Pedro Valdez,Alejandro Dura ´n,Konstantin Sobolev Academic Group on Concrete Technology,Faculty of Civil Engineering,Universidad Auto´noma de Nuevo Leo ´n,Monterrey,Mexico Received 2April 2006;received in revised form 13December 2006;accepted 13December 2006Available online 17January 2007AbstractThis research studied the diagonal tension behavior of 16beams reinforced with longitudinal bars and steel ﬁbers.The variable parameters included the concrete compressive strength and the percentage of ﬁbers (0%,0.5%,1.0%and 1.5%by volume).The beams were tested under static loads resulting in high diagonal tension stresses.The shear reinforcement was composed of stirrups instrumented with strain gages to detect the eﬀect of the ﬁbers on the strains.Research results indicate that as the ﬁber volume increases,the shear strength and the ductility of the beams increased,providing signiﬁcantly higher shear strength than speciﬁed by the ACI-318Code.Ó2007Elsevier Ltd.All rights reserved.Keywords:Concrete;Reinforcement;Fibers;Diagonal tension;Shear;Strain;Stress;Beam1.IntroductionThe majority of experimental studies of the shear beha-vior of reinforced concrete beams have focused primarily on the determination of stresses at which concrete cracks,and the contributions of the concrete and stirrups to the shear strength of the beam.The application of steel ﬁbers results in the improved ductility of reinforced concrete structural members such as beams and slabs [1,2].Fur-thermore,steel ﬁbers act as an additional shear reinforce-ment of concrete improving the stiﬀness,shear strength,shear toughness and resistance to diagonal cracking [3–6].Fiber reinforced concrete (FRC)can be described as a composite material consisting of a concrete phase and a small portion of discrete and discontinuous ﬁbers distrib-uted and oriented randomly within the concrete matrix [7].The design considerations for use of steel ﬁbers in con-crete with high and normal compressive strength are summarized in Refs.[8,9].Combination of steel and non-metallic ﬁbers was found to be extremely eﬀective inFRC beams based in high-strength concrete [10].The design criteria suggest that the stirrups must be placed to link the planes where the potential cracks are expected,however,at the high load levels this approach results in very small stirrup spacing.Therefore,an alterna-tive reinforcement such as steel ﬁbers would be eﬀective in such case to resist the diagonal tension stresses.The inves-tigation of steel ﬁber reinforced concrete beams with and without conventional stirrups demonstrated that the shear strength (corresponding to the ﬁrst crack)had increased sig-niﬁcantly due to the crack arrest eﬀect of the ﬁbers [11].The eﬀect of the steel ﬁbers on the behavior of high-strength concrete beams and partially prestressed beams under high-diagonal tension stresses was investigated [12–15].That work resulted in the analytical and empirical equations for the shear strength of these beams.The eﬀec-tiveness of steel ﬁbers to enhance the shear strength in ﬂanged sections of beams has been reported [16].It was concluded that the addition of ﬁbers can eﬀectively control the deﬂections,strains and rotations induced by the shear.Additional works investigated the eﬀect of cyclic loads [17],direct shear [18]and punching shear [19,20]on the perfor-mance of FRC beams.0958-9465/$-see front matter Ó2007Elsevier Ltd.All rights reserved.doi:10.1016/j.cemconcomp.2006.12.009*Corresponding author.E-mail address:cjuarez@ﬁc.uanl.mx (C.Jua´rez)./locate/cemconcompCement &Concrete Composites 29(2007)402–4082.Research signiﬁcanceThe present work describes the behavior of FRC beamswith stirrups subjected to high shear stresses.The main objective of this study was to determine the contribution of steel ﬁbers,used as partial replacement of stirrups.Tests on investigated FRC beams have demonstrated the advan-tageous eﬀect of ﬁbers in concrete beams subjected to high shear stresses.It was demonstrated that the load at the ﬁrst crack and the ultimate strength of the beam were enhanced.The reported results can have valuable implications for the design and application of concrete elements composed of FRC.3.Experimental program 3.1.Experimental setupThe experimental program included the test of 16rein-forced concrete beams with dimensions of 2000·150·250mm (79·6·10in.).The beams were designed to fail in diagonal tension.All beams were reinforced with three No.16longitudinal bars located at an eﬀective depth,d =216mm (81/2in.),and plain wire stirrups of diameter 6.35mm (1/4in.).The steel ﬁbers of 25mm (1in.)length were used at diﬀerent volumes (V f ),0%,0.5%,1.0%and 1.5%.Two ‘‘twin’’beams were cast for each dosage of ﬁber and concrete compressive strength combination.Fig.1shows the experimental setup and the locations of strain gages on two stirrups at their mid-height.The strain gages were placed at the assumed critical distance in shear,with an additional strain gage mounted on the longitudinal bars at a mid-span location.Beams were cast and vibrated in accordance with ASTM C 192[21].All beams were tested at 28days by applying two concentrated loads at a distance of 500mm (20in.)from the supports (Fig.1).Based on the prior experience,this type of loading provides the high shear stresses toward the extremes of the beams [22,23].The cracks and the cracking patterns visible on the surface of the FRC beams (with the width from 0.1mm)were detected with naked eye or magnifying glassand marked.The notations used in this work are according to ACI-318Code [24].3.2.MaterialsThe materials used in this research were portland cement type CPC 30R complying to ASTM C150.Crushed lime-stone aggregates were from Nuevo Leon,Mexico with a maximum size of 12.7mm (1/2in.)and a gradation in accordance with ASTM C 33.Fine aggregates were also crushed limestone with maximum size of 4.75mm (ASTM sieve No.4).Potable water was used for concrete prepara-tion and curing.Yield strength of the longitudinal steel reinforcement bars (ASTM A615)and plain wire stirrups was 420MPa (60ksi)and 330MPa (48ksi),respectively.Steel ﬁbers were deformed slit sheet according to ASTM A820.Fig.2shows the tension test results for the No.16bars and the plain wire.3.3.Concrete mixture proportioningSeveral concrete mixtures were tested at diﬀerent W/C and diﬀerent aggregate proportions following the recom-mendations of ACI-318Code [24].The ﬁnal concrete mixtures and corresponding test results are presentedinFig.1.Arrangement of the reinforcement and locations of the strain gages.C.Jua ´rez et al./Cement &Concrete Composites 29(2007)402–408403Table1.Totally,eight diﬀerent concrete mixtures wereused,half with a W/C=0.85and an average f0c ¼18:9MPa(2.7ksi)and another half with a W/C=0.55and an average f0c ¼36:7MPa(5.3ksi).The selected W/Cand strength levels are common to concrete structural ele-ments in Mexico.Therefore,the experimental variables were theﬁber volume fraction and an average concrete compressive strength.Duplicate‘‘twin’’beams were cast for each experimental node.3.4.Mixing,casting and curing of concreteThe mixing concrete was made in a90-l(3.18ft3)con-ventional mixer.First,theﬁne and coarse aggregates were mixed with complete amount of the absorption water to achieve the aggregates saturated surface dry(SSD)condi-tion.Then the cement and the design amount of water were added to the mixer;this process was followed by one min-ute mixing,one minute of rest and one minute of additional mixing.Theﬁbers were randomly added during the second period of mixing.After mixing,the concrete slump was measured and concrete was cast in the steel molds and compacted with an internal electrical vibrator.Concrete was continuously cured by ponding water on the top of the molds until the age of seven days.Following thisperiod,the beams were de-molded,sealed by water based curing compound and tested at the age of28days.4.Test results and discussionTest results of the investigated beams are shown in Table3and Figs.3–5.Shear behavior of beams(i.e.the stresses in longitudinal reinforcement and stirrups)was analyzed for diﬀerentﬁber volume fractions at two con-crete compressive strength levels.4.1.Nominal shear strengthThe nominal shear strength of the reference reinforced concrete beams withoutﬁbers can be obtained using the ACI318Code[24].For elements exclusively under shear andﬂexure,the shear strength of reference beams(V c,in kN)isV c¼ﬃﬃﬃﬃf0cpþ120q wV u dM ubwd7ð1ÞTable1Concrete mixture proportioningMaterials Mixture proportions(kg/m)3A-0.0A-0.5A-1.0A-1.5B-0.0B-0.5B-1.0B-1.5 Cement334334334334227227227227 Water184184184184193193193193Fine aggregates689684679674968961955948 Coarse aggregates1136112811201112919913906900 Fibers–3978117–3978117W/C ratio0.550.550.550.550.850.850.850.85 Compressive strength,(MPa)(ksi)36.7(5.3)37.2(5.4)36.9(5.4)35.8(5.2)18.7(2.7)19.7(2.9)18.3(2.7)18.8(2.7) Slump(mm)(in.)150(5.9)130(5.1)100(3.9)80(3.1)160(6.3)110(4.3)120(4.7)60(2.4) 1kg/m3=1.69lb/yd3;1MPa=0.145ksi.Notation:A or B designates the beam group with f0c ¼36:7MPa and18.9MPa,respectively,and theﬁber volume fraction is identiﬁed by the numbersfrom0.0to1.5.Table2Nominal shear strength according to ACI318code for the reference beamsBeam type f0c(MPa)V c(kN)F y(MPa)V s(kN)V n(kN) A36.739.0330.045.184.1B18.732.2330.045.177.31MPa=145.04psi;1kN=224.73lb.Table3Loads(P)corresponding to crack formation and shear strength of investigated beamsBeam type Load atﬁrstshear crack,(kN)Load atﬁrstﬂexure crack,(kN)Shear strength,(kN)A-0.0-132.632.687.8A-0.0-246.146.191.0A-0.5-346.130.790.9A-0.5-446.130.792.8A-1.0-561.946.498.0A-1.0-651.630.990.3A-1.5-751.630.996.5A-1.5-856.736.197.7B-0.0-130.930.965.5B-0.0-230.936.163.7B-0.5-336.120.685.1B-0.5-441.320.674.8B-1.0-551.625.893.2B-1.0-646.420.690.3B-1.5-746.430.9100.6B-1.5-851.630.998.01kN=224.73lb.Notation:A or B designates the beam group with f0c¼36:7MPa and 18.9MPa,respectively,the middle numbers from0.0to1.5are related to ﬁber volume fraction;and the additional number identiﬁes each beam within the set.404 C.Jua´rez et al./Cement&Concrete Composites29(2007)402–408whereV c60:3ﬃﬃﬃﬃf0cpb w dð2ÞandV u dM u61:0ð3ÞThe nominal shear strength carried by the stirrups(V s)is deﬁned asV s¼A v f y dsð4ÞTable2summarizes the results of the nominal shear strengths(V n,in kN)of the reference beams which isV n¼V cþV sð5Þ4.2.Eﬀect of steelﬁbersAs it was expected,the incorporation ofﬁbers improves the toughness of the composite[23].Fig.3shows that FRC beams exhibit higher ductility and higher shear strength when compared to the reference beams.The group A of beams demonstrates up to two-fold improvement of the ductility vs.the group B.However,the main eﬀect ofﬁber reinforcement was related to the improvement of the shear strength as the volume fraction ofﬁbers increased.The group B beams with V f=1.5%showed the shear strength increase of54%vs.the reference beams,and for the group A beams with V f=1.5%,the increase was12%.For the A and B beams with V f=1.5%,the test shear strength of the FRC beams was higher than that assumed by the ACI-318 Code nominal shear strength,by17%and30%,respec-tively.In these calculations the strength reduction factor, /=0.75was not used for the design.C.Jua´rez et al./Cement&Concrete Composites29(2007)402–408405It was conﬁrmed that the addition ofﬁbers reduces the width of diagonal tension cracks,improving the transmis-sion of shear load and redistribution of the stresses between the concrete matrix,ﬁbers and stirrups.On the other hand, it can be observed that the increase in concrete compressive strength provides only9%improvement of nominal shear strength.It was demonstrated that the strains in the longitudinal bars increased as the V f increased.Test results presented in Fig.4indicate that with rise of V f,the shear load required to attain the yield strain of longitudinal reinforcement was also increased.This behavior was mainly observed for thebeams with lower concrete strength(f0c ¼18:9MPa),whenthe reference beams failed without yielding of the longi-tudinal reinforcement.The longitudinal reinforcementyielded in all beams with higher concrete strength(f0c ¼36:7MPa)prior to their failure in shear,as shown in Fig.4.This could be explained by the improved bonding between theﬁbers and the concrete matrix,resulting in the enhancement of ductility.In both cases,the important eﬀect of the addition ofﬁbers is in the improvement ofductility,as shown in Fig.3.It can be observed that for concrete with f0c¼36:7MPa,the longitudinal reinforce-ment in beams with V f>1.0%reached the ultimate strain of three times greater than that of the reference beams (Fig.4).The strains in the stirrups shown in Fig.5indicate that prior to cracking of the beams,the stresses are relatively low,and,in most cases,are in compression.After cracking, the stresses in the stirrups increased.The eﬀect of theﬁbers on corresponding strains is small,even through for beamswith f0c¼18:9MPa higher shear strength was observed at the increased V f(Fig.5).This behavior can be attributed to the location of the strain gages,since in all tested beams the diagonal cracks did not occur at the exact position of the gage.With increase in the volume ofﬁbers the number of cracks also increases,yet resulting in a signiﬁcantly reduced crack width(Fig.6).The load level atﬁrst shear crack increases in all beams with increase inﬁber content.406 C.Jua´rez et al./Cement&Concrete Composites29(2007)402–408However,theﬁrst cracks inﬂexure appeared at the same load levels for all investigated beams.Therefore,the com-pressive strength orﬁber content had little eﬀect on this parameter.Importantly,the addition ofﬁbers was very eﬀective to hinder the shear crack formation;this eﬀect is somehow improved for the composites based on concrete of higher compressive strength(Table3).The failure of the beams occurred in the concrete com-pression zone when the diagonal tension cracks propagated to the compression zone bridging the opposite zones of load application(Fig.6).5.ConclusionsBased on the results of the experimental work,the fol-lowing conclusions were made:1.The application of steelﬁbers as an additional reinforce-ment allows a substantial increase of the shear strength and the ductility of FRC beams vs.the reference beams.2.The presence ofﬁbers increases the load level at whichthe longitudinal reinforcement yields.3.The main eﬀect of the steelﬁbers is related to theincrease of the beam’s shear strength,the increase in the load level corresponding to theﬁrst shear crack, and therefore,improved shear behavior when compared with the reference beams with stirrups.4.The shear strength of theﬁber reinforced concretebeams withﬁber volume of1.5%is about30%higher than the nominal design capacity computed by the ACI318Code.5.Increasedﬁber volumes allow the development of multi-ple cracking in all investigated beams;smaller crack widths were detected for beams with higher concrete compressive strength due to denser concrete matrix,bet-ter bond to theﬁbers and also due to the load transfer across the cracks.AcknowledgementsAuthors acknowledge theﬁnancial support from the Program for Enhancement of the Professorate(PROMEP) of the Public Education Directorate of Me´xico.The contri-bution of the Institute of Civil Engineering,Faculty ofC.Jua´rez et al./Cement&Concrete Composites29(2007)402–408407Civil Engineering of the Universidad Auto´noma de Nuevo Leo´n is highly appreciated.The participation of under-graduate students of the Faculty of Civil Engineering actively involved in this project is acknowledged. References[1]Khuntia M,Stojadinovic B.Shear strength of reinforced concretebeams without transverse reinforcement.ACI Struct J2001;98(5): 648–56.[2]Swamy RN,Jones R,Chiam TP.Inﬂuence of steelﬁbers on the shearresistance of lightweight concrete I-beams.ACI Struct J1993;90(1): 103–14.[3]Shin SW,Oh JG,Ghosh SK.Shear behavior of laboratory-sized highstrength concrete beams reinforced with bars and steelﬁbers,SP-142-10,American Concrete Institute;1994,p.181–200.[4]Shah SP.Fiber reinforced concrete.Concr Int,Am Concr Inst1990;12(3):81–2.[5]Frosch RJ.Behavior of large-scale reinforced concrete beams withminimum shear reinforcement.ACI Struct J2000;97(6):814–20. [6]Mirsayah AA,Banthia N.Shear strength of steelﬁber-reinforcedconcrete.ACI Struct J2002;99(5):473–9.[7]Metha K,Monteiro P.Concreto;estructura,propiedades y materi-ales,Instituto Mexicano del Cemento y Concreto;1998.p.197–286.[8]ACI Committee544,Design considerations for steelﬁber reinforcedconcrete,ACI Manual of concrete practice,part5,1999.p.544.4R-1–544.4R-18.[9]RILEM TC162-TDF,Test and design methods for steelﬁbrereinforced concrete sigma-epsilon-design method,Materials and structures,RILEM Publications SARL,vol.36,No.262;2003.p.560–67.[10]Noghabai K.Beams ofﬁbrous concrete in shear and bending:experiment and model.J Struct Eng2000;126(2):243–51.[11]Narayanan R,Darwish e of steelﬁber as reinforcement.ACIStruct J1987;84(3):473–9.[12]Ashour SA,Hasanain GS,Wafa FF.Shear behavior of high-strengthﬁber reinforced concrete beams.ACI Struct J1992;89(2):176–84. [13]Padmarajaiah SK,Ramaswamy A.Behavior ofﬁber-reinforcedprestressed and reinforced high-strength concrete beams subjected to shear.ACI Struct J2001;98(5):752–61.[14]Tan KH,Murugappan K,Paramasivam P.Shear behavior ofﬁberreinforced concrete beams.ACI Struct J1993;90(1):3–11.[15]Tan KH,Paramasivam P,Murugappan K.Steelﬁbers as shearreinforcement in partially prestressed beams.ACI Struct J1995;92(6): 643–52.[16]Swamy RN,Bahı´a HM.The eﬀectiveness of steelﬁbers as shearreinforcement.Concr Int,Am Concr Inst1985;7(3):35–40.[17]Kwak KH,Suh J,Hsu TCT.Shear-fatigue behavior of steelﬁberreinforced concrete beams.ACI Struct J1991;88(2):155–60.[18]Valle M,Bu¨yu¨ko¨ztu¨rk O.Behavior ofﬁber reinforced high-strengthconcrete under direct shear.ACI Struct J1993;90(2):122–33. [19]Theodorakopoulos DD,Swamy N.Contribution of steelﬁbers to thestrength characteristics of lightweight concrete slab-column connec-tions failing in punching shear.ACI Struct J1993;90(4):342–55. [20]Shaaban AM,Gesund H.Punching shear strength of steelﬁberreinforced concreteﬂat plates.ACI Struct J1994;91(3):406–14. [21]ASTMC192–02,Practice for making and curing concrete testspecimens in the laboratory,American Society for Testing and Materials,Philadelphia;1999.p.6.[22]Park P,Paulay T.Reinforced concrete structures.John Wiley andSons;1975.p.288–94,769.[23]ACI Committee544,state-of-the-art onﬁber reinforced concrete,ACI manual of concrete practice,part5,1998;p.544.1R-1–544.1R-66.[24]ACI318M-05,Building code requirements for structural concreteand commentary,American Concrete Institute;2005.p.139–86 [chapter11].408 C.Jua´rez et al./Cement&Concrete Composites29(2007)402–408。

土木工程专业英语带译文

如果钢筋等高强度的材料置于混凝土中，则复合材料钢筋混凝土不仅能抵抗压缩，还能抵抗弯曲和其他直接拉伸作用。钢筋混凝土部分的混凝土抗压缩和钢筋抗张力可以制成几乎任何形状和大小的建筑构件。
13
Key characteristics Three physical characteristics give reinforced concrete its special
12
Chapter 6
If a material with high strength in tension, such as steel, is placed in concrete, then the composite material, reinforced concrete, resists not only compression but also bending and other direct tensile actions. A reinforced concrete section where the concrete resists the compression and steel resists the tension can be made into almost any shape and size for the construction industry.
钢筋混凝土是由混凝土，钢筋（钢筋），钢筋网（钢筋网），钢板网，钢板或纤维组成，这些被用来加强混凝土的张力。它由法国园丁约瑟夫·莫尼尔于1849年发明，并于1867年获得专利。混凝土仅指用钢或钢加固的混凝土。 5
• Other materials used to reinforce concrete can be organic and inorganic fibres as well as composites in different forms. Concrete is strong in compression, but weak in tension, thus adding reinforcement increases the strength in tension. In addition, the failure strain of concrete in tension is so low that the reinforcement has to hold the cracked sections together. For a strong, ductile and durable construction the reinforcement shall have the following properties:

土木工程专业英语-Reinforced Concrete Structures

As a result, financial savings（财务的节约）due to rapid construction may more than offset（足以抵消）increased material costs. Any measures designer can take to standardize the design and forming（加工）will generally pay off（使人得益）in reduced overall costs. In many cases the long-term economy（长期的经济性）of the structure may be more important than the first cost. As a result, maintenance（维护）and durability（耐久性）are important considerations.
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。在很多情况下，结构长期的经济性可能比初始费用更重要。因此，维护和耐久性是重要的考虑因素。
Suitability of Material for Architectural and Structural Function A reinforced concrete system frequently allows the designer to combine the architectural and structural functions（功能）. Concrete has the advantage that it is placed in a plastic condition（塑性状态）and is given the desired shape and texture（密度）by means of the forms and the finishing techniques（加工技术）. This allows such elements（构件）as flat plates or other types of slabs to serve as load-bearing elements while providing the finished floor and ceiling surface（楼面和顶棚面）. 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 or shape is governed（决定）by the designer and not by the availability of standard manufactured members.

Recent improvements to release of kc concrete model

Recent Improvements to Release III of theK&C Concrete ModelJoseph M. Magallanes1, Youcai Wu1, L. Javier Malvar2, and John E. Crawford11Karagozian & Case, Burbank, CA2Naval Facilities Engineering Service Center, Port Hueneme, CAAbstractRecent improvements are made to Release III of the Karagozian & Case (K&C) concrete model. This three-invariant plasticity and damage-based constitutive model is widely used to model a number of materials, including normal and lightweight concrete, concrete masonry, and brick masonry, to compute the effects of quasi-static, blast, and impact loads on structures. This most recent version of the model, made available starting with LS-DYNA®v971 as *MAT_CONCRETE_DAMAGE_REL3, incorporates a number of improvements to the original model that are described in this paper. The model now exhibits: (a) an automatic input capability for generating the data for generic concrete materials and (b) methods to reduce mesh-dependencies due to strain-softening. A simple method is implemented to regularize the fracture energy by internally scaling the damage function for the generic concrete model parameters. For user-defined material parameters, a method is developed that can preserve fracture energy using the results of either single-element or multi-element simulations. Finally, concrete loading rate effects are discussed and guidance is provided on properly modeling such effects with the model.1.IntroductionThe K&C concrete (KCC) material model was first released in 1994 [1-3]. This first version represented a significant overhaul of the concrete material model (Model 16) in the DYNA3D finite element (FE) program. This overhaul included (1) adding a third, independent failure surface based on a Willam-Warnke three-invariant formulation (a change from the original two-invariant formulation), (2) introducing a radial stress path for the strain rate enhancement algorithm, (3) adding a fracture energy dependent strain in tension, and (4) fixing several major discrepancies in the original model.The second release of the KCC model was released in 1996 [4]. The Release II model extended the previous model to include shear dilation (i.e., increase in volume due to shearing). The formulation introduced in this version allowed the model to be partially associative, fully associative, or non-associative, facilitating a more accurate representation of the behavior of reinforced concrete structures. In addition, the strain rate effect algorithm was modified to allow for implementation of different strain rate enhancement factors, or dynamic increase factors (DIFs), in tension and compression [5].This third release of the model [6], made available in LS-DYNA starting with v971 as *MAT_CONCRETE_DAMAGE_REL3 [7-8], incorporates a number of improvements to the original formulation, which are described in this paper. First, the automatic input capability for generating the model parameters for “generic” concrete materials is discussed. Second, methods included in the model to reduce mesh-dependencies due to strain-softening are described. Finally, concrete loading rate effects are discussed and guidance is provided on properly modeling rate effects with the model.The principal advantage that this model provides, in comparison with other constitutive models used for concrete-like materials, is that it is relatively simple and numerically robust. It is capable of reproducing key concrete behaviors critical to blast and impact analyses and is also quite easily calibrated to laboratory data. The modeling capabilities afforded by the improvements in Release III are evidenced in numerous recent studies in the literature [9-12]. The discussions presented in this paper are especially warranted in light of recent material testing conducted by K&C and others and to further detail features of the model.2. Automatic Parameter GenerationUnder sponsorship of various U.S. Department of Defense agencies, extensive mechanical characterization tests were completed for several concrete materials. Material tests included unconfined uniaxial compression and tension tests, triaxial compression tests under various levels of confinement, hydrostatic compression tests, and a number of strain path tests. These types of material characterization tests are described in [13]. Default values for the KCC model were derived based on these and other data derived from the literature (e.g., see [14]). The default concrete exhibited an average compressive strength, 'c f , slightly over 45 MPa (or 6,500 psi). To generalize the KCC model for other concrete materials, its parameters are adjusted using the concrete strength parameters to obtain the appropriate relationships between the concrete properties, e.g., relationships between tensile and compressive strength, and between bulk modulus and compressive strength, among others [15]. For the deviatoric strength, the KCC model uses a simple function to characterize three independent failure surfaces that define the yield, maximum, and residual strength of the material. Three parameters i a 0, i a 1, and i a 2 (9 parameters total for the three surfaces) define each of the failure surfaces:()p a a p a p F i i i i ⋅++=210 (1) where, p is the pressure (i.e., mean normal stress) and i F is the i th of three failure surfaces.For hardening, the plasticity surface used in the model is interpolated between the yield and maximum surfaces based on the value of the damage parameter, λ. For softening, a similar interpolation is performed between the maximum and residual surfaces.The parameters in Eqn. (1) were calibrated to the original data and provide a best fit for that material; these are designated o i a 0, o i a 1, and o i a 2. The scaling coefficient, r , is defined as theratio of the interpolated 'c f (i.e., the material strength one desires to model) to the compressivestrength of the original material characterized in the laboratory, 'co f , or: ''coc f f r = (2) For any selection of 'c f , the failure surface parameters are scaled using r as follows: r a a o i i ⋅=00 (3a)o i i a a 11= (3b) a a o i i 22= (3c)The failure surface obtained from the generic concrete is shown in Fig. 1a for three different concrete compressive strengths. The Equation of State (EOS) is also scaled using r and is shown in Fig. 1b for the same three concrete compressive strengths. Triaxial compressionstress path (50 MPa)Unconfined compression stress path(a) Maximum failure surface. (b) Equation of state. Fig. 1. Strength and volumetric responses obtained from the generic concrete model.The tension softening parameter, 2b , is also scaled using simple relationships for concrete. The 2b model parameter, which controls the behavior of the model in strain softening, is adjusted to obtain the fracture energies (f G ) recommended by the CEB [16]. These are shown in Table 1. In Release III, the fracture can be entered in one of two ways. First, a user may directly enter 2b values, using Table 1 as guidance. Alternatively, the model can internally compute estimates for the fracture energies of Table 1 by entering 'c f and the maximum aggregate size (MAS ).This automatic parameter generation capability was developed to provide analysts with a simple tool from which to model concrete when little is known other than the concrete’s compressive strength. There are, naturally, a number of limitations to this feature:• Recent experimental studies have shown that concrete’s shear strength can be quite variable, especially for confining pressures greater than 50 MPa [13, 17-19]. Based on these studies, a concrete’s failure surface can be affected by a number of other factors including the porosity and moisture content. Unfortunately, there is currently insufficient data from which to formulate functions for these other parameter effects.• The volumetric response (i.e., the EOS) for concrete is also variable. Although material characterization tests are expensive and time-consuming, calibrating the KCC model to specific material characterization data may be warranted in some situations.• The superficial similarities between concrete and a number of concrete-like materials such as concrete and brick masonry tempt many to use the generic concrete fit to model masonry structures. Although the materials are indeed similar, the behaviors of concrete and brick masonry have subtle but important differences. The main difference is the lack of coarse aggregate in the latter—coarse aggregate tends to slow down crack propagation resulting, for example, in higher tensile strengths. Concrete masonry tends to behave more akin toTable 1. Mode I tensile fracture energies for concrete based on CEB recommendations.lightweight concrete, where the coarse aggregate is often weaker than the cement paste, allowing crack propagation through the aggregates. A recent study showed that the KCC model can provide excellent results if properly calibrated for these materials [20].3.Strain-softeningIn the presence of strain-softening, FE predictions will not provide objective solutions unless localization limiters are introduced. A number of methods have been proposed including direct length scale techniques (e.g., the “crack band” fracture model [21-22]), introduction of artificial viscosity or rate dependency [23], non-local methods [24-25], or microplane methods [26]. All of these methods have some limitations: the crack band assumes a localization width (which could be the element size), the rate dependency is limited to a rate range and loses effectiveness in the quasi-static limit, non-local methods rely on a zone of influence, and the microplane method is limited by the angle between microplanes. Some of the approaches (e.g. the last two) can be computationally intensive; hence a simple method was implemented in the model. The crack band method was implemented in two ways in Release III: the first is used for the generic concrete model and the second is intended for advanced use of the model where sufficient data is available from which to directly calibrate the model parameters.For the generic concrete model, the crack band is assumed to occur within one element. The regularization is accomplished by internally scaling the softening branch of the damage function, ()λη, using the average size of each element. Results illustrating the effectiveness of the approach are shown in Fig. 2. Here the results of single element simulations loaded in unconfined uniaxial tension (UUT) under velocity control are shown for four different element sizes. On the left of the figure, the stress versus strain response of the elements shows that for small elements, the softening is slow, while for larger elements, the softening is accelerated. On the right, the fracture energy, which is obtained by integrating the stress versus displacement response for each element, is plotted as a function of the displacement. Despite a small error, the fracture energies for each of the elements are very close to that in Table 1. Note that this regularization has limitations: it is not implemented when the element size exceeds 250 mm (the softening branch becomes vertical and the energy dissipated can no longer be reduced to match f G ), or when the elements are much smaller than the localization width (when the softening branch may approach a plastic limit, resulting possibly in excessive energy dissipation, e.g., in penetration problems).VerticalvelocityFig. 2. Single element response in UUT using the generic concrete model (40 MPa, 16 mm MAS).For user-defined material parameters, this regularization scheme may be insufficient if the parameters of ()λη are significantly different from the generic concrete material. The fracture energy regularization surface (FERS) approach was developed to provide means from which to preserve fracture energy in such cases. The FERS is a three-dimensional response surface, which the KCC model can use to compute a value for 2b that considers the element size and the user-input f G value. The FERS is defined as:3222231111222221112112221102x x x x x x x x b ⋅+⋅+⋅+⋅+⋅⋅+⋅+⋅+=ββββββββ (4)where, 1x is the average element size (internally calculated for each element in LS-DYNA), 2x is the desired f G value, and i β are the parameters of the FERS. In practice, one may executenumerous single-element or multi-element LS-DYNA simulations, using various mesh sizes and values for 2b , and the i β parameters for Eqn (4) can be obtained using standard regressionmethods to obtain suitable FERS parameters.An example is shown in Fig. 3, where the resulting fracture energies were computed for aboutb parameters were one hundred UUT simulations using a single element, whose size and2varied. The LS-DYNA results are shown as dots in the plot. The FERS surface is also shown in the figure, the parameters of which were obtained using nonlinear regression. The parameters of the FERS surface can then be input to the model, using a *DEFINE_LOAD_CURVE, which the KCC model uses to regularize the fracture energy for each element in the model.A key benefit to this approach lies in the fact that the FERS need not be calibrated to single-element simulations, but can be based on the results for multi-element models under dynamic loads. In practice, this method may implicitly compensate for some of the limitations we discussed related to the localization width.Results of LS-DYNAsimulationsFracture energyregularization surface(FERS)Fig. 3. Fracture energy regularization surface fit to single element simulations.4.Rate effectsLoading rate effects in concrete have been recognized for decades [5, 27-28]. For typical structural response problems that were the focus of the concrete structures research community during this time, the DIF versus strain rate relationship for most constitutive models were calibrated directly to peak strength data like those obtained using the split-Hopkinson pressure bar (SHPB) [29]. Concrete data obtained from such tests exhibit a two branch behavior when plotted with normalized peak strength versus strain rate [5, 16, 27-28]. (Note that for brittle materials like unconfined concrete, strain rates in SHPB tests are rarely constant even though they are typically reported as such.)Rate effects in concrete are due initially to moisture, and, at higher strain rates, to inertia effects [30]. Hence the initial branch of the DIF (e.g. below about 1.0 s-1) should typically be included, as the constitutive model does not generally include the effects of moisture. The second branch of the DIF can be captured by the FE model, assuming adequate mesh resolution to do so. Consequently, there have been two schools of thought on this second branch, one advocating not using it to prevent duplication of inertia effects, and another one advocating its use to ensure proper dissipation. In practice, FE models are capable of capturing the inertia effects in compression (e.g. from the mass of the outer cylinder elements resisting motion laterally), but not as well in tension (since the model cannot capture the aggregate interlocking that propagates the microcracking and energy dissipation beyond the localization zone).These concepts are illustrated in Fig. 4, where simulations of a well characterized concrete material were loaded in compression and tension. Two idealized loading variants are performed: (a) a quasi-static loading (1.0e-4 s-1) and (b) a dynamic loading pulse that induces global strain rates of approximately 100 s-1. Three different mesh sizes are examined using the rate-independent version of the KCC model (i.e., by setting the DIF versus strain rate curve equal to unity). In compression, there is a clear increase in strength computed in the simulation when loaded dynamically as compared with the quasi-static case. This indicates that the FE model captures an inertia effect. For tension, no such increase is discernable, which indicates that a DIF function is needed to properly represent the inertia effect. Recently analytic and experimental studies have reinforced these notions [31-33].Fig. 5 demonstrates that, in compression, only the initial branch of the DIF is needed to properly represent data from SHPB tests. Here, a 76.2 mm diameter SHPB compression test is simulated with a detailed FE model of the test (Fig. 5a) using KCC model parameters calibrated to quasi-static material characterization data for that material [13]. The actual loading pulses measured by the incident bar strain gauge are applied to the model for three different loading pulse levels designated “low”, “medium”, and “high” strain rates, and the results are compared with the output stress wave measured by the transmitter bar strain gauge. Three models are used to obtain numerical results for each of the three compression loading pulses: (1) Model 1, which uses the rate-independent model, (2) Model 2, which uses the modified CEB DIF with both branches of the function, and (3) Model 3, which uses the modified CEB DIF with only the first branch of the function (Fig. 5b). The resulting transmitted pulses are shown in Fig. 5c that can be compared with the experimental data. As expected, Model 1 produces peak strengths that are lower than the experiments (because that model does not account for the rate effects from moisture in the sample). Model 2 produces much higher peak strengths (in essence, double counting for inertia in the sample). Model 3, on the other hand, provides good agreement with the dataset, even though the DIF function (using only the first branch) was not calibrated to this specific concrete (i.e., the modified CEB model was used). These DIF factors (i.e., using both branches in tension and only the first one in compression) are representative of those needed as input to the model. It is possible, using this type of high-quality SHPB data for a particular concrete material, to improve DIF parameter estimates using parameter identification techniques.5.ConclusionsThis paper described recent improvements to Release III of the K&C concrete model, which was made available in LS-DYNA starting with v971. An automatic input capability is now provided as a tool for generating model parameters for generic concrete materials when little is known other than the concrete’s compressive strength. There are, naturally, a number of limitations to this approach, which were reviewed and should be considered prior to deploying the generic model parameters. In addition, the model now includes improved methods from which to reduce mesh-dependencies due to strain-softening. Two methods are available: the first is used for the generic concrete model and the second is intended for advanced use of the model where sufficient data is available from which to directly calibrate the model parameters. The latter is attractive in that it provides a means from which to calibrate the parameters using the results of single or multi-element FE models. Lastly, concrete loading rate effects were discussed and guidance was provided on properly characterizing those effects with the KCC model. An example was shown that provides excellent results with test data.Velocity loading varies:(1) Quasi-static loading (1e-4 1/s)(2) Dynamic loadingpulse Transmission bar Loading bar Concrete sampleFixed for (1)NRB for (2)Velocity loading varies: (1) Quasi-static loading (1e-4 1/s)(2) Dynamic loadingpulse Transmission bar Loading barConcrete sample Fixed for (1)NRB for (2)Notch(a) Compression model. (b)Tension model.2 mm 5 mm 15 mmPressure fringes near peak strength(c) Quasi-static compression loading.(d) Dynamic compression loading.Crack bandnormal to load(e) Quasi-static tension loading. (f) Dynamic tension loading. Fig. 4. Simulations of a concrete sample subjected to compression and tension; all results arecomputed using the rate-independent version of the KCC model.Transmission bar Incident barConcretesampleCompression pulse(a) Axial stress fringes in the SHPB.(b) Input DIF versus strain rate curves (compression).Model 1Experimental data (Magallanes et al., 2009)High strain rate Med. strain rateLow strain rateModel 3Model 2(c) Transmitted stress pulses as a function of time.(Each of the groups of results is time shifted so that they may be examined individually). Fig. 5. Comparisons of compression SHPB data with simulations using the KCC model.6. AcknowledgementsThe comments and suggestions of Mr. Ken Morrill of K&C regarding the approaches presented in this paper are greatly appreciated. The authors would also like to acknowledge Mr. Ahsan Samiee of the University of California at San Diego for constructing the FE mesh of the split Hopkinson Pressure Bar.7.References[1]Malvar, L.J., Crawford, J.E., Wesevich, J.W., Simons, D. (1994), "A New Concrete Material Model forDYNA3D," TM-94-14.3, Report to the Defense Nuclear Agency, Karagozian and Case, Glendale, CA.[2]Malvar, L.J., Crawford, J., Simons, D., Wesevich, J.W. (1995), “A New Concrete Material Model forDYNA3D,” Proceedings, 10th ASCE Engineering Mechanics Conference, Vol. 1, Boulder, CO, pp. 142-146. [3]Malvar, L.J., Crawford, J.E., Wesevich, J.W., Simons, D. (1997), "A Plasticity Concrete Material Model forDYNA3D," International Journal of Impact Engineering, Vol. 19, No. 9/10, pp. 847-873.[4]Malvar, L.J., Crawford, J.E., Wesevich, J.W., Simons, D. (1996), “A New Concrete Material Model forDYNA3D - Release II: Shear Dilation and Directional Rate Enhancements,” TR-96-2.2, Report to the Defense Nuclear Agency, Karagozian and Case Structural Engineers, Glendale, CA. (Limited Distribution)[5]Malvar, L.J., Crawford, J.E. (1998), “Dynamic Increase Factors for Concrete,” Proceedings of the 28th DDESBExplosive Safety Seminar, Orlando, FL, August.[6]Livermore Software Technology Corporation (2007a), “LS-DYNA Keyword User’s Manual: Volume I,”Version 971, Livermore, CA.[7]Livermore Software Technology Corporation (2007b), “LS-DYNA Keyword User’s Manual: Volume II,Material Models,” Version 971, Livermore, CA.[8]Crawford, J.E., Malvar, L.J. (1997), “User's and Theoretical Manual for K&C Concrete Model,” TR-97-53.1,Karagozian and Case Structural Engineers, Glendale, CA. (Limited Distribution)[9]Magallanes, J.M. (2008), “Importance of concrete material characterization and modeling to predicting theresponse of structures to shock and impact loading,” Structures Under Shock and Impact X, Eds. N. Jones, WIT Press, Southampton.[10]Malvar, L.J., Morrill, K.B., Crawford, J.E. (2004), “Numerical Modeling of Concrete Confined by FiberReinforced Composites,” Journal of Composites for Construction, Vol. 8, No.4, pp. 315-322.[11]Bao, X., Li, B. (2010), “Residual Strength of Blast Damaged Reinforced Concrete Columns,” InternationalJournal of Impact Engineering, Vol. 37, No. 3, pp. 295-308.[12]Tu, Z., Y. Lu, Y. (2009), “Evaluation of typical concrete material models used in hydrocodes for high dynamicresponse simulations,” International Journal of Impact Engineering, Vol. 36, No. 1, pp. 132-146.[13]Magallanes, J.M., Martinez, R.M., Neser, A., Schreiber, D., Zencker, U. (2009), “A Comprehensive MaterialTesting Program for Characterizing Concrete Behaviors Under Static and Dynamic Loads,” Proceedings of the 13th International Symposium on the Interaction of the Effects of Munitions with Structures (ISIEMS), Brühl, Germany.[14]Chen, W.F. (1982), Plasticity in Reinforced Concrete, McGraw Hill, New York.[15]Malvar, L.J., Crawford J.E., Morrill, K.B. (1999), “K&C Concrete Material Model, Release III: AutomatedGeneration of Material Model Input,” TR-99-24, Karagozian and Case Structural Engineers, Glendale, CA.(Limited Distribution)[16]Comité Euro-International du Béton - Fédération Internationale de la Précontrainte (1990), CEB-FIP ModelCode 90, Redwood Books, Trowbridge, Wiltshire, Great Britain (ISBN 0-7277-1696-4).[17]Imran, I., Pantazopoulou, S.J. (1996), “Experimental Study of Plane Concrete under Triaxial Stress,” ACIMaterials Journal, Vol. 93, No. 6, pp. 589-601.[18]Gabet, T., Malecot, Y., Daudeville, L. (2008), “Triaxial behavior of concrete under high stresses: Influence ofthe loading path on compaction and limit states,” Cement and Concrete Research, Vol. 38, pp. 403-412.[19]Vu, X. H., Malecot, Y., Daudeville, L., Buzaud, E. (2009), “Experimental analysis of concrete behavior underhigh confinement: Effect of the saturation ratio,” International Journal of Solids and Structures, Vol. 46, pp.1105-1120.[20]Magallanes, J.M., Morrill, K.B., Crawford, J.E. (2008), “Finite element models for the analysis and design ofCMU walls to blast loads,” Proceedings of the 80th DDESB Explosives Safety Seminar, Palm Springs, CA. [21]Bažant, Z.P., Oh, B.H. (1983), “Crack bank theory for fracture of concrete,” Materials and Structures, Vol. 16,pp. 155-177.[22]Oliver, J. (1989), “A Consistent Characteristic Length for Smeared Cracking Models,” International Journal forNumerical Methods in Engineering,” Vol. 28, pp. 461-474.[23]Sandler, I., Wright, J. (1984), “Summary of strain-softening,” In Theoretical Foundations for Large-ScaleComputations of Nonlinear Material Behavior, DARPA-NSF Workshop, Edited by N. Nemat-Nasser, pp.285-315, Northwestern University.[24]Pijaudier-Cabot, G., Bažant, Z.P. (1987), “Nonlocal Damage Theory,” Journal of Engineering Mechanics, Vol.113, No. 10, pp. 1512-1533.[25]Belytschko, T., Bažant, Z.P., Hyun, Y.W., Chang, T.P. (1986), “Strain-Softening Materials and Finite-ElementSolutions,” Computers and Structures, Vol. 23, No. 2, pp.163-180.11th International LS-DYNA® Users Conference Simulation (1) [26]Bazant, Z.P., Prat, P.C. (1988), "Microplane Model for Brittle-Plastic Materials, I. Theory and II. Verification,"Journal of Engineering Mechanics, Vol. 114, No. 10, pp. 1672-1702.[27]Ross, C.A., Thompson, P.Y., Tedesco, J.W. (1989), “Split-Hopkinson Pressure-Bar Tests on Concrete andMortar in Tension and Compression,” ACI Material Journal, Vol. 86, No. 5, 9pp. 475-481.[28]Ross, C.A., Jerome, D.M., Tedesco, J.W., Hughes, M.L. (1996), “Moisture and Strain Rate Effects on ConcreteStrength,” ACI Materials Journal, Vol. 93, No. 3, pp. 293-300.[29]Gray, G.T. (1999), “Classic Split-Hopkinson Pressure Bar Technique: Chapter 6A,” Los Alamos NationalLaboratory Technical Report, LA-UR-99-2347.[30]Malvar, L.J., Ross, C.A. (1999), Closure to the Discussion of “Review of Static and Dynamic Properties ofConcrete in Tension,” by Toutlemonde F. and Rossi P., ACI Materials Journal, Vol. 96, No. 5, pp. 614-616. [31]Cotsovos, D.M., Pavlović, M.N. (2008), “Numerical investigation of concrete subjected to compressive impactloading. Part 1: A fundamental explanation for the apparent strength gain at high loading rates,” Computers and Structures, Vol. 86, No. 5, pp. 145-163.[32]Zhang, M., Wu, H.J., Li, Q.M., Huang, F.L. (2009), “Further investigation on the dynamic compressive strengthenhancement of concrete-like materials based on split Hopkinson pressure bar tests. Part I: Experiments,”International Journal of Impact Engineering, Vol. 36, No. 12, pp. 1327-1334.[33]Kim, D.J., Sirijaroonchai, K., El-Tawil, S., Naaman, A.E. (2010), “Numerical simulation of the Split HopkinsonPressure Bar test technique for concrete under compression,” International Journal of Impact Engineering, Vol.37, No. 2, pp. 141-149.3-47。

钢筋混凝土梁的剪切和斜拉最新

最后，应力达到一定程度，足以沿垂直于局部拉应力的方向出现另外的拉裂缝。
The mode of failure is influenced by the shear span to effective depth ratio given by a / h0 where a is the distance between the support and the nearest concentrated load
剪跨比影响梁的破坏方式。剪跨比的计算公式： a
h0
在这里，a表示支座与距离最近的集中力的距离
The diagonal crack, once formed, spread either immediately or at only slightly higher load, traversing the entire beam from the tension reinforcement to the compression face, splitting it into two and failing the beam.
其他的内力，包括未开裂的混凝土产生的Vcz，纵向钢筋的销栓作用Vd。
大多情况下，出于设计经济性考虑，弯曲构件应该能够充分发挥其抗弯性能，而不是由过早的剪切破坏限制其具有的强度。
Typically, web reinforcement is provided in the form of vertical stirrups, spaced at varying intervals along the axis of the beam depending on the requirements, as shown in Figure 4.15.

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。

土木工程专业英语课后答案到lesson18

Unite 12、Translate the following phrases into Chinese /English .（1）Compression Member受压构件（2）critical buckling load 临界屈曲荷载（3）the slenderness ratio 细长比（4）stub column 短柱（5）reduced modulus 简化模量（6）Effective length 计算长度（7）Residual stress 残余应力（8）Trial-and-error approach 试算法（9）Radius of gyration 回转半径（10）Tangent modulus 切线模量3、Translate the following sentence into Chinese.(1)This ideal state is never achieved in reality, however, and some eccentricity of the load is inevitable.然而，在现实中,这种理想状态从来没有实现，一些荷载偏心是不可避免的(2)In many instances the members are also called upon to resist bending, and in these cases the member is a beam-column.在许多情况下，构件同样需要能够抵抗弯矩，在这些情况下，构件被称之为梁柱。

(3)If the member is so slender that the stress just before buckling is below the proportional limit---that is, the member is still elastic---the critical buckling load is given by Q.如果该构件很细长以至于在压曲前的应力低于比例极限---也就是说，该构件仍然是弹性状态---该构件的该临界屈曲荷载就可以由公式Q给出。

Observations on the Behavior of Low-Rise Reinforced Concrete Buildings

COFFEE ZONE, COLOMBIA, JANUARY 25 EARTHQUAKEObservations on the Behavior of Low-Rise Reinforced Concrete BuildingsBy Santiago Pujol , Julio Ramírez and Alberto SarriaINTRODUCTIONOn January 25, 1999, at approximately 1:19 PM (local time), an earthquake of magnitude 5.9 m b 1, 6.0 M L 2, struck the “coffee zone” in Colombia. This paper presents observations on the damage suffered by low-rise reinforced concrete buildings in the cities of Armenia and Pereira. The observations presented are part of a study based on data collected during a five-day visit to the mentioned cities. Recommendations intended to avoid in the future the most frequently observed structural problems are presented.SCOPEThe objective of the ongoing study, from which only the main field observations are presented here, is to correlate seismic vulnerability of reinforced concrete, low-rise, monolithic buildings with their dimensions and arrangement of columns and walls.SEISMICITY AND GEOLOGICAL CONTEXT Geographic Location and Regional SeismicityThe location of the epicenter of the January 25, 1999, earthquake as estimated by Instituto de Investigación en Geociencias, Minería y Química, (INGEOMINAS),2 is shown in Figure 1. Armenia, a 223,0003 people city, is about 15 km north from the estimated epicenter (4.41N, 75.72W). Pereira, a 355,0003 people city, is approximately 50 km north from the same point.In Colombia, the Andes are divided into three mountain ridges. Both, Armenia and Pereira, lay on the western hills of the central ridge, which is characterized by the presence of several volcanoes. The Del Ruiz volcano, known for the catastrophic Armero mudslide of 1985, is among those. 1 Observatorio Sismológico del Suroccidente (OSSO), 1999. .co.2 Instituto de Investigación en Geociencias, Minería y Química, (INGEOMINAS), 1999..co.3From an official census made in 1993Colombia and, in general, the northwestern corner of South-America, is a complex tectonic environment. Three tectonic plates interact there: Nazca, South-America and Caribbean (Sarria, 1995). The Nazca plate is believed to move from west to east at about 2.4 inches per year. The South-America plate moves from east to west at a relative velocity of 0.4 to 0.8 inches per year. The Caribbean plate moves in the WE direction at a relatively smaller velocity. The stress field generated by the interaction of these plates is evidenced by activity along several geological faults. Some of these faults have been well identified. That is the case of the Romeral fault (See Figure2), which crosses Colombia from South to North along more than 1000 km and through six major cities: Pasto,Popayán, Armenia, Pereira, Manizales and Medellín (Sarria, 1995). A rupture along a branch of this fault generated the 03/31/1983, Popayán earthquake, which caused 300 casualties and losses of 300 million dollars (0.8% of Colombia’s gross internal production in 1982). The January 25, 1999, earthquake seems to have been generated by a rupture along another branch of the Romeral fault: Cauca-Almaguer. Its strike and deep have been estimated to be N15ºE and 73ºE respectively 4. The rupture appears to be left lateral, which indicates a displacement in the NS direction of the Andes block with respect to the eastern planes of Colombia.Seismic HistoryThe “coffee region” has a rich seismic history. Table 1 contains data on the main seismic events occurred in the region in the last 20 years. Figure 2 shows the location of the epicenters of earthquakes with magnitudes (M s )equal or larger than 4 occurred in Colombia between 1566 and 1995.Table 1. Main seismic events occurred in the Coffee Region in the last 20 yearsNo Date Mm/dd/yy Magnitude DepthKm111/25/1979 6.4 (---)---202/08/1995 6.4 (m b )90301/25/1999 5.9 (m b )5-154 Espinoza A., Areas Ltda., Bogotá, Colombia. Personal communication, February 15, 1999.Geology and General Soil CharacteristicsIn general, the soils in the region affected by the earthquake may be described as deposits of volcanic ashes of about 60 ft laying on conglomerates or igneous rocks. These volcanic ashes are very cohesive soils with values of cohesion of about 7-14 psi 5.The zones that were affected the most in Armenia and Pereira coincide with those where buildings lay on old fills of bad quality.Ground Accelerations MeasuredThe maximum horizontal accelerations measured in Pereira were 0.08G on rock and 0.30G on fills.6 Preliminary information indicates that, in Armenia, values of 0.59G and 0.47G would have been measured at ground level for horizontal and vertical peak ground acceleration, respectively.5AftershocksAs of February 9, 1999, more than 90 aftershocks have been registered. The main aftershock occurred about 4h: 21min after the main shock and had a magnitude of 5.8 (M L).7 The location of the aftershocks has migrated towards the north, i.e., towards Armenia. No pre-shocks were recorded.EMERGENCY RESPONSEThe January 25, 1999 earthquake affected 35 cities, caused more than 900 casualties and injured at least 4000. It has been estimated that about 200,000 people were left without shelter (El Colombiano, Feb. 1, 1999). Preliminary estimates indicate that reconstruction of the infrastructure of the cities affected will cost more than 500 million dollars. (El Tiempo, Jan. 29, 1999). This is about 0.5% of the 1996 gross national product o f Colombia; a country with an estimated fiscal deficit of 2% of this year’s projected gross national product (El Tiempo, Jan. 29, 1999).In Armenia, the police headquarters suffered partial collapse. The fire station collapsed. The water, telephone and electricity lines suffered severe damage. Traffic through the main access roads and airport operations were interrupted. Government buildings were evacuated. Because of these events, the first days after the earthquake in the city were very chaotic. For similar reasons, the emergency in other cities of the region could not be properly managed either. In Circasia and Córdoba the hospital buildings collapsed. The Calarcá hospital suffered partial collapse.In Pereira, on the other hand, there was a basic infrastructure for emergency response in place. This permitted organized efforts to be conducted toward rescue and clean-up operations. This preparation can be attributed to the lessons learned from the earthquakes of 11/25/1979 and 02/08/1995.A daunting task now facing not only Pereira and Armenia but all 35 cities affected is that of reconstruction, particularly, of the low income housing infrastructure.PAST MITIGATION EFFORTSIn the years from 1950 to 1980, the city of Armenia experienced the largest construction development in the last decades. But only since 1984 and in response to the damage caused by the 1983 Popayán earthquake, application of seismic design recommendations by the Colombian Association of Seismic Engineering is enforced by a law of the Republic of Colombia. A revision of these recommendations was made in 1998 (Colombian Association of Earthquake Engineering, 1998). Design provisions are made according to estimations of seismic risk that suggest a division of the Colombian territory into three zones with different hazard levels as shown in Figure 3. Observe that the cities of Armenia and Pereira lay on a zone with estimated high seismic hazard. Design ground acceleration in5 Espinoza A., Areas Ltda., Bogotá, Colombia. Personal communication, February 15, 1999.6 OSSO, 1999. .co.7 INGEOMINAS, 1999. .co.this zone varies from 0.25G to 0.4G. Therecommended design ground acceleration forPereira and Armenia corresponds to the lowerbound of this range.The Calima, 1995 earthquake caused damage inPereira. Consequently, a local mitigation programwas deployed which benefits not only Pereira butalso Dosquebradas and Santa Rosa de Cabal.Mitigation efforts before the 1999 earthquake alsoincluded retrofitting of some structures in Armenia.A detail showing how columns of a building atUniversity of Quindío were upgraded is shown inFigure 4. In this figure, one of the original columnsin the roof level is shown surrounded by steel inpreparation for the casting of concrete around theoriginal section. The behavior of this buildingduring the January 25 earthquake was acceptable.It suffered relatively light damage of nonstructuralmasonry walls and moderate damage of the roof.In addition to triggering efforts to enforce the useof seismic design guidelines, the 1983 Popayánearthquake together with the 1985 Armeromudslide led to the development of the NationalOffice for Emergency Response.This office was successfully tested by the Paez, June 1994 earthquake.At the same time that the National Office for Emergency Response wasestablished, a national network of seismographs together with over 100accelerometers, most of them digital, began to be established throughoutColombia. Unfortunately, both emergency response and detection effortshave been underfunded in recent years. It is hoped that the lessonslearned from the Jan. 25, 1999 earthquake will bring new impetus to bothprojects.OBSERVATIONSMost of the structural damage observed in low-rise, reinforced concretebuildings may be classified into four categories:Captive ColumnsIt is common practice in Colombia to use unreinforced masonry walls,about 5 inches thick, as partitioning system. The interaction betweenthese walls and the structure seems to be often ignored. This observationwas frequently corroborated by the failures of many captive columns inArmenia as shown in Figures 5 to 8.In view of the potential consequences of ignoring the problem, anexplanation is presented next.Exact determination of the forces induced in a column of a structure subjected to strong ground motion is not an easy task. A pragmatic approximation, very useful in design, is to assume that the element reaches its flexuralcapacity at both ends and under oposite curvatures. The maximum probable shear that can therefore act on a givensection of such an element is limited to twice the plastic moment capacity of the section divided by its clear height.When a nonstructural element restrains the column along part of its height only, the maximum probable shear increases almost in inverse proportion to the reduction in clear height. For instance, if a column is restrained by a retaining wall in a first story, a practice observed in several buildings in Armenia (Figure 6), so that its clear height is one fourth of its original clear length, the maximum probable shear that could eventually act on this element would be four times higher than that calculated ignoring the possible interaction between the wall and the ck of transverse reinforcementColumns with very small amounts of transversereinforcement, as the one shown in Figure 9, were observedto have experienced severe damage. Observe that, in thiscase, only one layer of transverse reinforcement wasprovided within the zone where the element developed largeinelastic deformations. This was a 13.5 in x 13.5 in columnand the spacing of the stirrups was about 12 in. Notice thatbesides the insufficient amount of transverse reinforcement,its anchorage was not adequate. Ninety degrees hooks notanchored in the core of the column could have limited thedevelopment of the yield capacity of the plain ties provided.Damage related to the interaction between structural and nonstructural elementsFigure 10 shows a column in the first story of a public school inArmenia. In this case, the location of the inclined crack seems toindicate that the direction of movement was such that one couldnot relate the failure of this column with the possible effect of theadjacent discontinuous wall. The slenderness of the member, inturn, indicates that the shear stress that could have been developedshould not be expected to be high. However, it seems plausiblethat the discontinuity generated by the failure of the adjacentcontinuous wall may have triggered the failure of the column.Deficient detailingFigures 11 and 12 serve to stress the importance of good detailing.Figure 11 shows a column in which the architectural flare at thetop moved the critical section away from the joint region. Thismade any transverse reinforcement that could have been providednear the joint ineffective and, at the same time, the clear height ofthe column was reduced.Figure 12 shows a construction joint at the base of a column in the first story of a reinforced concrete building in downtown Armenia. Observe the evident lack of continuity, the presence of rather unusual hooks, the use of plain bars, and the absence of transverse reinforcement.Additional observationsSeveral additional observations are worth discussing:- Very fragile partitions consisting of unreinforced, brick walls were observed in Pereira and Armenia.Their use in very flexible reinforced concrete frames seemed quite common. Columns with aspect ratios –ratio of distance between points of maximum and minimum curvature to effective depth- of more than 4 were frequently observed. In general, severe damage to the masonry was a common consequence of the Jan. 25, 1999earthquake (See Figure 13). In the most fortunate cases, this only caused economical losses. Some of the 1998 revisions to the seismic design recommendations for Colombia (Colombian Association of Earthquake Engineering, 1998) were intended to remedy this.- Figure 14 shows what was left of a residentialbuilding in Armenia after the January 25earthquake. It was “identical” to the ones stillstanding next to the debris. It is obvious that theconsequences could have been worse. Thestructure consisted of reinforced concrete flatslabs, slender reinforced concrete columns andunreinforced masonry walls. The inadequacy ofthe mechanism that could provide lateralresistance in these buildings was made evidentby the January 25 quake.- The remarkable importance of structuralredundancy cannot be overemphazised. Itrepresents the difference between collapse andsevere structural damage without collapse(Figures 15 and 16).- As important as design provisions, repair guidelines represent a critical component of anyefforts toward the reconstruction of urbaninfrastructure.-The absence of reinforced concrete shear walls in the twenty buildings surveyed was noted.ACKNOWLEDGMENTSThe writers want to express their gratitude with Mario F. De La Pava, Luz E. Ocampo and Luis C. Martínez, Society of Engineers of Quindío; Ana Campos, Margarita Ochóa and Jaime Guzmán, Project of Seismic Risk of Pereira, Dosquebrads and Santa Rosa De Cabal; Gabriel Fernández, University of Illinois; Adolfo Alarcón, INGEOMINAS; Jorge E Durán, Gómez-Cajiao y Asociados; Augusto Espinoza, Areas; Omar D. Cardona, Colombian Society of Earthquake Engineering; Josef Farbiarz and Jorge E. Polanco, National University of Colombia at Medellín; Martha C. Vélez, Integral; Pedro F. Pujol, Gerinsa; and Marcia Collins, Tracy Mavity, Vincent P. Drnevich and Mete A. Sozen, Purdue University.REFERENCES“Armenia Despertó con Nuevas Réplicas,” El Colombiano, February 1, 1999.Colombian Association of Earthquake Engineering, 1998, Normas Colombianas de Diseño y Construcción Sismo Resistente, 4 vols., Santa Fe de Bogotá, Colombia.Sarria Alberto, 1995, Ingeniería Sísmica, Second Edition, Ediciones Uniandes and ECOE Ediciones, Santa Fe de Bogotá, Colombia, 569 p.“Se revisarán Proyectos de Desarrollo Acordados con el BID,” El Tiempo, January 29, 1999.。

(完整版)土木工程专业英语翻译

(1)Concrete and reinforced concrete are used as building materials in every country. In many, including Canada and the United States, reinforced concrete is a dominant structural material in engineered construction.(1)混凝土和钢筋混凝土在每个国家都被用作建筑材料。

在许多国家，包括加拿大和美国，钢筋混凝土是一种主要的工程结构材料。

(2)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.(2) 钢筋混凝土建筑的广泛存在是由于钢筋和制造混凝土的材料，包括石子，沙，水泥等，可以通过多种途径方便的得到，同时兴建混凝土建筑时所需要的技术也相对简单。

(3)Concrete and reinforced concrete are used in bridges, building of all sorts, underground structures, water tanks, television towers, offshore oil exploration and production structures, dams, and even in ships.(3)混凝土和钢筋混凝土被应用于桥梁，各种形式的建筑，地下结构，蓄水池，电视塔，海上石油平台，以及工业建筑，大坝，甚至船舶等。

Unit 7 Properties of Concrete and Reinforced Concrete译

7混凝土是自然的,不需要单独防火保护制度。因为它的质量,它也可以作为有效的屏障,传声。
8在浏览网页的内容、具体,但不幸的是消极方面很重,我们会注意到,一个混凝土结构费很大一部分,其容量仅仅携带本身。本文通过具体的密度较低,同时保持高质量的水平,通常都导致了价格上涨。然而,使用轻质混凝土有时会导致总体经济。
6最好的结构用而言,对钢筋混凝土的特点,在这些建筑材料,需要连续性和或刚性。它有一个整体质量是自动进行固定或连续的连接。这些时刻就是如此,许多耐关节低层钢筋混凝土建筑物不需要一个次要的支撑体系为横向负载。从本质上来说,混凝土梁加入了混凝土柱的方式以非常不同的方式从钢材和木材件的加盟,以及敏感设计师不会无视这一差别。(这些言论并不适用于预制结构元素,它们往往是不参加了一个连续方式。)
4论文和其他相关主题有充分覆盖在这个小册子上,“设计和控制混凝土混合物、出版的《普通硅酸盐水泥协会。这是一个极好的参考,治疗两个混凝土配合比设计和相应的施工实践。美国混凝土学会出版一份广泛采用代码指定的钢筋混凝土结构的要求。
5混凝土是众所周知的可成形的或可塑造的结构材料。相较于其他材料,这是很容易做到的曲线成员和表面混凝土。它没有内在的纹理,但采用的质地的材料,所以它可以形成范围广泛应用于表面研究。它也相对便宜,无论是从原材料和劳动力,和普通硅酸盐水泥的基本原料是可得到的世界各地。(值得注意的是,无论如何,必要的加固酒吧为混凝土可能不是现成的欠发达国家)。
10适当的混凝土浇筑ห้องสมุดไป่ตู้所依赖于周围的天气情况下。极高的温度和更重要的是,那些低于或接近冰冻会做出具体的工作是很困难的。
1混凝土是一种人造的砾岩石头组成的本质上四成份;普通硅酸盐水泥、水、沙子和粗集料。水泥和水相结合,使糊的沙子和石头,维系在一起。理想的情况是,蕴是分层次的体积酱是至少,仅仅是周围每一件有一层薄薄的。大多数结构混凝土是石混凝土结构的轻质混凝土,但约有三分之二的密度(石混凝土)变得越来越流行。

同济大学出版社土木工程专业英语10单元翻译

断裂韧性结构钢是坚韧的；也就是说，它们既有强度又有延性。一根钢构件加荷至大变形时将仍然能够承受大的力。这是非常重要的特性，因为这意味着钢构件在制作和安装期间能承受大的变形而不断裂—这就允许它们被弯曲、锤击、剪切以及在上面冲孔而没有明显的损害。材料吸收大量能量的能力称为韧性。
Additions to Existing Structures Steel structures are quite well（相当）suited to having additions made to them. New bays（节间）or even entire（整个）new wings（翼）can be added to existing steel frame buildings, and steel bridges may often be widened.
高强度钢材每单位重量的高强度意味着结构的重量将是小的。这个事实对大跨的桥梁、高层建筑以及有着薄弱地基条件的结构具有重要意义。
Uniformity The properties of steel do not change appreciably（明显地）with time, as do those of reinforced-concrete structure.
在对已有结构的添加钢结构相当适合对其自身进行添加。新的节间、甚至整个新的翼能被添加到已有的钢框架建筑上，因此钢桥常常可以被加宽。
Miscellaneous Several other important advantages of structural steel are: (a) ability to be simple connection devices（方法） including welds and bolts; (b) adaptation to prefabrication（预制）; (c) speed of erection; (d) ability to be rolled into a wide variety of （各种各样的） sizes and shapes; (e) fatigue strength; (f) possible reuse（再利用）after a structure is disassembled（分解）, and (g) scrap value（残余价值）, even though not reusable（可再利用的）in its existing form. Steel is the ultimate recyclable（可循环的）material.

土木专业英语unit7

任何一个国家建筑的材料都是混凝土和钢筋混凝土，在很多国家中，包括美国，加拿大，在工程结构中钢筋混凝土式主要的材料。

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 constructure. And the economy of reinforced concrete compared to other forms of construction. 钢筋混凝土结构的通用性质主要取决于钢筋的用量以及混凝土，砂砾，细砂，及水泥的构成成分，与混凝土结构相比需要相对的简单的技能，并且钢筋混凝土建筑比其他结构的建筑更经济。

concrete混凝土和钢筋混凝图被用于桥梁、各种房屋、地下结构、水箱、电视塔、海洋石油勘探、工业结构、水坝乃至船舶。

Mechanics of reinforced concrete钢筋混凝土的机械性能混凝土有较好的抗压性能，而抗拉性较差。

As a result ,cracks develop wherever loads,or restrained shrinkage or temperature changes, give rise to tensile stresses in excess of the tensile strength of the concrete. 所以，无论是荷载或抵抗收缩或温度改变所产生的拉应力都会超过混凝土的抗拉强度。

In the plain concrete beam, the monments due to applied loads are reisted by an internal tension-compression couple involving tention in the concrete. Such a beam fails very suddenly and completely when the first crack forms. 在普通混凝土梁中，由于施加荷载所产生的力矩是由内部的拉力和压力形成的力偶来抵抗的，这个力偶中包含了混凝土中的拉力。

钢筋混凝土的损坏原因与防治措施

The Causes and Prevention Measures of Reinforced Concrete Damage
1.2　碱集料反应
应而破坏的现象，这种反应降低混凝土的力学性能和承载力，加大混凝土内部劣化程度，危害性强，修补难度大。

碱集料反应的发生一般具备三个条件：混凝土碱性大，掺杂过量碱物质，主要是水泥、外加掺和料的不合理搭配导致；集料中含有过多碱活性物质，易于混凝土发生化学反应，破坏结构；混凝土调配比例不恰当，水分含量高，高于
更易进行。

因此从预防手段考虑，加强碱活性检和湿度检测，避免集料碱活物超标，保持混凝土
常是防止混凝土破坏的有效措施。

1.3　混凝土冻融破坏
潮湿地区，尤见于高纬度严寒、极寒地区。

冻融破坏是物理发生过程，其作用机理如下：混凝土内部存有诸多。

土木工程专业英语unit 6(1)

铝合金早在1933年就应用于桥梁结构了，它极大地降低了桥梁的自重，但是由于造价昂贵并没有被广泛使用。
The principle portions(parts) of a bridge may be said to be the “superstructure” and “substructure”.
1. substructure n. 下部结构 superstructure 上部结构
2. predominate vi. 占支配地位；在……中占优n势.元帅
3. precipitation n. 沉淀，降雨量 4. marshal vt. 安排，调度，整理
v. arrange/dispatch order/organize
Aluminum alloys,( which were used in bridges as early as 1933,) greatly reduce the dead weight of the bridge, but they are not widely used because they are relatively expensive.
的
21. octagonal adj. 八边（角）形的；n. 八边（角）形 22. terminus n. 终点站，终点，边界 23. embankment n. 路堤，岸堤，堤 24. sill n. 底梁，底座，基础 25. batter n. 倾斜，坡度，倾斜度 (v.smash/slap猛击、
桥梁的主要结构被称为上部结构和下部结构
This divisionnce, since in many bridges there is no clear dividing line (分界线)between the two.

什么是钢筋混凝土英语作文

什么是钢筋混凝土英语作文What is Reinforced Concrete?Reinforced concrete is a composite material made of concrete and steel reinforcement. The concrete is poured into a mold, or formwork, and steel reinforcement bars, or rebars, are placed within the concrete before it sets. The steel reinforcement provides additional strength and stiffness to the concrete, making it suitable for use in a wide range of construction applications.The use of reinforced concrete dates back to the mid-19th century, when French engineer Joseph Monier began experimenting with various materials to reinforce concrete. Monier's experiments led to the development of the first reinforced concrete structures, including bridges and buildings.Today, reinforced concrete is used in a wide range of construction projects, from high-rise buildings and bridgesto dams and retaining walls. It is a popular choice for construction because it is strong, durable, and relatively inexpensive.The Advantages of Reinforced Concrete。

土木1094班专业英语翻译

一、英译中1.the particular problem in reinforced concrete structures is therefore the determination of theapprepriate flexural rigidity ei for a member consisting of two materials with properties and behavior as widely different as steel and concrete因此钢筋混凝土结构中的特殊问题是由钢筋和混凝土这两种特性和行为大不相同的材料组成的构件的抗弯刚度的确定。

2.while concrete is best employed in a manner which utilizes its favorable compressionstrength ,its tension strength is also of consequence in variety of connection.。

混凝土最好的使用状态则是良好的压缩强度，但它的拉伸强度在各种连接中也是至关重要的。

3.various machine parts can be washed very clean and will be as deep as new ones when theyare treated by ultrasonics,no matter how dirty and irregularly shaped they may be .各种机器零件可以清洗的很干净，用超声波处理后，无论多么的脏，形状多么不规则，都会像新的一样。

4. a footing is eccentrically loaded if the supported column is not concentric with the footingarea or if the column transmits at its juncture with the footing not only a vertical load but alsoa bending moment.如果支撑柱与基础底面不对中或者在柱子与基础的连接处不仅传递一个竖向荷载还传递一个弯矩，那么基础就长寿偏心荷载作用。

重庆大学土木专业英语重点句

第一册Unit1Usually the objective of our analysis will be the determination of the stresses, strains, and deformations produced by the loads: if these quantities can be found for all values of load up to the failure load, then we will have obtained a complete picture of the mechanical behavior of the body.通常，我们分析的目的是要确定由于荷载所产生的应力、应变和变形；如果对于破坏荷载前的各荷载值都能求得应力、应变和变形的大小，我们就能对物体的力学性能得到完整的概念。

The historical development of mechanics of materials is a fascinating blend of both theory and experiment, with experiments pointing the way to useful results in some instances and with theory doing so in others.材料力学的历史是理论和实验两者最好的结合。

在某些情况下，试验导致有益的成果，而在另外一些情况下，理论又会做到这一点。

These forces will be continuously distributed over the cross section, analogous to the continuous distribution of hydrostatic pressure over a submerged surface.这些力沿整个截面连续分布，类似于筋膜面上液体静压力的连续分布。