Unit 5 Reinforced Concrete

1、 Specialized English for Civil Engineering实用土木工程专业英语实用土木工程专业英语中国建材工业出版社中国建材工业出版社 Unit 5 Reinforced Concrete 第第5章章 钢筋混凝土钢筋混凝土Main contents Text AIntroduction to Reinforced Concrete 钢筋混凝土介绍 Translate some important sentences 翻译句子 Special difficulties 难点讲解 Translation Skills -长句的分译与合译流畅表达 Writing Skill

2、s -英文摘要的一般要求 Plain concrete, commonly known as concrete, is an intimate mixture of binding material, fine aggregate, coarse aggregate and water. This can be easily moulded to desired shape and size before it looses plasticity and hardens. Plain concrete is strong in compression but weak in tension.

3、素混凝土，通常简称为混凝土，它是粘合料、细骨料、粗骨料和水的均匀混合物。混凝土在失去黏性硬化前，可以制成各种形状和尺寸。素混凝土抗压强度高，抗拉强度低。 Hence reinforcement is provided in the concrete wherever tensile stress is expected. The best reinforcement is steel, since tensile strength of steel is quite high and the bond between steel and concrete is good. The compos

4、ite material of steel and concrete now called RC act as a structural member and can resist tensile as well as compressive stresses very well. 因此在预期会产生拉应力的混凝土中加入加劲物。最佳的加劲物是钢材，因为它的抗拉强度很高，且钢材与混凝土之间的粘结力很高。钢与混凝土复合材料，也叫钢筋混凝土作为结构构件共同工作，可同时抵抗拉应力与压应力。 Answer the following questions： （1）What did Coignet do in

5、 the development of structural prefabricated and reinforced concrete? （1） Coignet 在发展结构预制混凝土和钢筋混凝土方面做了什么贡献？ Franois Coignet was a French industrialist of the 19th century, a pioneer in the development of structural prefabricated and reinforced concrete. Coignet was the first to use iron-reinforced c

6、oncrete as a technique for constructing building structures. In 1853 Coignet built the first iron reinforced concrete structure, a four story house in the suburbs of Paris. Coignet是法国第十九世纪的实业家，是发展结构预制混凝土和钢筋混凝土方面的先驱。Coignet是第一个用钢筋混凝土技术建造建筑物。1853年Coignet建造第一个钢筋混凝土结构，一栋在巴黎郊区的四层楼的房子。 Many different type

7、s of structures and components of structures can be built using reinforced concrete including slabs, walls, beams, columns, foundations, frames and more. Reinforced concrete can be classified as precast or cast-in-place concrete. 钢筋混凝土可以用来建造多种不同类型的结构与结构构件，包括板，墙，梁，柱，基础，框架等。钢筋混凝土可以划分为预支混凝土和现浇混凝土。 Desi

8、gning and implementing the most efficient floor system is key to creating optimal building structures. Small changes in the design of a floor system can have significant impact on material costs, construction schedule, ultimate strength, operating costs, occupancy levels and end use of a building. 设

9、计与建造最有效的楼盖是制造最优建筑结构的关键。在楼盖设计中很小的变化都会在材料成本，工期，极限强度，运营成本，居住水平和最终使用方面有着巨大的影响。 Without reinforcement, constructing modern structures with the concrete material would not be possible. 没有钢筋，就不可能用混凝土材料建造现代结构。Rebars of Sagrada Famlias roof in construction建设中的圣家族教堂屋顶的钢筋 （2） What is concrete? （2）什么是混凝土？ Concr

10、ete is a mixture of coarse（stone or brick chips）and fine（generally sand or crushed stone）aggregates with a paste of binder material（usually Portland cement）and water. 混凝土是由胶凝材料（通常是硅酸盐水泥）和水将粗骨料（石头或碎砖 ）和细骨料（一般用砂或碎石）胶结而成。 When cement is mixed with a small amount of water, it hydrates to form microscopi

11、c opaque crystal lattices encapsulating and locking the aggregate into a rigid structure. The aggregates used for making concrete should be free from harmful substances like organic impurities, silt, clay, lignite etc. 当水泥与少量水混合，会发生水化作用，形成微观结晶体，把集料封锁在内，形成刚性结构。制作混凝土的集料应不含有害物质，如果有机杂质，粉土，粘土，褐煤等。 Typica

12、l concrete mixes have high resistance to compressive stresses about 4,000psi （28MPa）; however, any appreciable tension（e.g., due to bending）will break the microscopic rigid lattice, resulting in cracking and separation of the concrete. For this reason, typical nonreinforced concrete must be well sup

13、ported to prevent the development of tension. 典型的混凝土具有较高的抗压强度4000磅/平方英寸（28兆帕）；但是，任何明显的拉力（例如，由弯曲引起的）将破坏微观刚性晶体，导致混凝土开裂和分离。为此，典型的素混凝土必须有良好的支撑，以防止拉力的产生。 If a material with high strength in tension, such as steel, is placed in concrete, then the composite material, reinforced concrete, resists not only c

14、ompression 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. 如果把抗拉强度高的材料，比如钢材放入混凝土中，那么合成的材料钢筋混凝土不仅能承受压力，也能抗弯或者别的直接拉力作用。截面中

15、混凝土承受压力，钢材承受拉力，在施工中可制造出几乎各种形状和尺寸。 （3） What are the properties of reinforced concrete? （3）钢筋混凝土有什么性能？ The following physical characteristics give reinforced concrete its special properties: The coefficient of thermal expansion of concrete is similar to that of steel, eliminating large internal stress

16、es due to differences in thermal expansion or contraction. 下面的物理特性使钢筋混凝土具有特殊性能： 混凝土热膨胀系数与钢材的相似，能消除由于热膨胀或收缩的差异而产生的巨大的内部应力。 When the cement paste within the concrete hardens, this conforms to the surface details of the steel, permitting any stress to be transmitted efficiently between the different ma

17、terials. Usually steel bars are roughened or corrugated to further improve the bond or cohesion between the concrete and steel. 当混凝土中的水泥浆硬化时，它与钢表面花纹相互咬接，允许任何应力在不同材料间有效地传输。通常钢筋的粗糙表面或波纹能进一步提高钢筋与混凝土之间的粘结力。 The alkaline chemical environment provided by the alkali reserve（KOH, NaOH）and the portlandite（ca

18、lcium hydroxide）contained in the hardened cement paste causes a passivating film to form on the surface of the steel, making it much more resistant to corrosion than it would be in neutral or acidic conditions. 碱性物质（氢氧化钾，氢氧化钠）提供的碱性化学环境和包含在硬化水泥浆内的氢氧钙石（氢氧化钙）导致钢表面钝化膜的形成，使得它会比在中性或酸性条件下更耐腐蚀。 When the cem

19、ent paste exposed to the air and meteoric water reacts with the atmospheric CO2, portlandite and the calcium silicate hydrate（CSH）of the hardened cement paste become progressively carbonated and the high pH gradually decreases from 13.512.5 to 8.5, the pH of water in equilibrium with calcite（calcium

20、 carbonate）and the steel is no longer passivated. 当暴露在空气和大气水中的水泥浆与大气中的二氧化碳发生反应时，硬化的水泥浆中的氢氧化钙和水化硅酸钙（CSH）逐渐被碳化，并且高pH值逐渐从13.512.5降低至8.5，这是一个与方解石（碳酸钙）相平衡的水的酸碱度，并且钢不再发生钝化 。 （4） What are the chief reasons for the failure of reinforcement bars in concrete? （4）混凝土中钢筋失效的主要原因是什么？ As a rule of thumb, only to g

21、ive an idea on orders of magnitude, steel is protected at pH above 11 but starts to corrode below 10 depending on steel characteristics and local physicochemical conditions when concrete becomes carbonated. Carbonatation of concrete along with chloride ingress is amongst the chief reasons for the fa

22、ilure of reinforcement bars in concrete. 一般来说，只强调数量级的话，钢在pH值高于11时受到保护，但低于10时便开始受到侵蚀，这取决于当混凝土碳化时钢的特性和当地的物理化学条件。混凝土碳化和氯离子的侵蚀是混凝土中钢筋失效的主要原因。Rebar for foundations and walls of sewage pump station.污水泵站的基础和墙中放置的钢筋。 The relative cross-sectional area of steel required for typical reinforced concrete is usua

23、lly quite small and varies from 1% for most beams and slabs to 6% for some columns. Reinforcing bars are normally round in cross-section and vary in diameter. Reinforced concrete structures sometimes have provisions such as ventilated hollow cores to control their moisture & humidity. 对典型的钢筋混凝土截

24、面，所需的钢筋相对截面积通常很小，从绝大多数梁的约为1%，到对某些柱子达到6%。钢筋的截面一般为圆形，直径各有不同。钢筋混凝土结构有时会有些设施比如通风孔芯以控制其湿度。 Distribution of concrete (in spite of reinforcement) strength characteristics along the cross-section of vertical reinforced concrete elements is inhomogeneous. 沿着钢筋混凝土竖向构件横截面的混凝土强度分布（即使不考虑钢筋）是不均匀的。 （5）What is mech

25、anism of Composite Action of Reinforcement and Concrete? （5）钢筋和混凝土的复合作用机制是什么？ （5）What is mechanism of Composite Action of Reinforcement and Concrete? （5）钢筋和混凝土的复合作用机制是什么？ A h e a v y r e i n f o r c e d concrete column, seen before and a f t e r t h e concrete has been cast in place around the rebar

26、 cage The reinforcement in a R.C. structure, such as a steel bar, has to undergo the same strain or deformation as the surrounding concrete in order to prevent discontinuity, slip or separation of the two materials under load. Maintaining composite action requires transfer of load between the concre

27、te and steel. 钢筋混凝土结构中的钢筋必须经受与周围混凝土相同的应变或变形，以防止在荷载作用下两种材料发生间断、滑动或分离。要维持复合机制需保证混凝土与钢材间的荷载传递。 The direct stress is transferred from the concrete to the bar interface so as to change the tensile stress in the reinforcing bar along its length. This load transfer is achieved by means of bond（anchorage）an

28、d is idealized as a continuous stress field that develops in the vicinity of the steel-concrete interface. 直接应力从混凝土传递到钢筋接触面从而改变了钢筋沿其长度方向的拉应力。该荷载传递是通过粘结（锚固）的方法实现的，并且被理想化为在钢-混凝土界面附近产生的连续应力场。 （6） What is the main requirement for safety against bond failure? （6）对抗粘结破坏的主要安全要求是什么？ Because the actual bond

29、stress varies along the length of a bar anchored in a zone of tension, current international codes of specifications use the concept of development length rather than bond stress. 因为实际的粘结应力会随着受拉区的钢筋长度变化而变化，所以目前的国际规范使用锚固长度这个概念，而不是粘结应力。 The main requirement for safety against bond failure is to provid

30、e a sufficient extension of the length of the bar beyond the point where the steel is required to develop its yield stress and this length must be at least equal to its development length. 防止粘结破坏主要安全要求就是钢筋长度延伸足够长，这个长度超出钢筋产生屈服应力所需的长度，并且必须至少等于其锚固长度。 However, if the actual available length is inadequat

31、e for full development, special anchorages must be provided, such as cogs or hooks or mechanical end plates. The same concept applies to lap splice length mentioned in the codes where splices (overlapping) provided between two adjacent bars in order to maintain the required continuity of stress in t

32、he splice zone. 如果实际长度不足锚固长度，就须采取一些特殊的锚固措施例如钝齿、弯钩或机械端板。同样的概念适用于规范规定的搭接长度，即为保证搭接区域应力的连续性，在两根相邻钢筋间的重叠搭接。A heavy reinforced concrete column, seen before and after the concrete, has been cast in place around the rebar cage.巨型钢筋混凝土柱在钢筋笼周边浇灌混凝土的前后对照图Rebar constructed to properly reinforce a beam element,

33、awaiting concrete to be poured. 用于加固梁的钢筋正等待混凝土浇注。 A beam bends under bending moment, resulting in a small curvature. At the outer face (tensile face) of the curvature the concrete experiences tensile stress, while at the inner face (compressive face) it experiences compressive stress. 梁在弯矩作用下受弯，产生小的

34、曲度。在曲线的外侧（受拉侧）混凝土承受拉应力，在内侧（受压侧）承受应力。 （7） What is a singly reinforced beam? （7）什么是单筋梁？ A singly reinforced beam is one in which the concrete element is only reinforced near the tensile face and the reinforcement, called tension steel, is designed to resist the tension. 单筋梁是指只在受拉区中配置钢筋的混凝土构件，并用受拉钢筋来承受

35、拉应力。 A doubly reinforced beam is one in which besides the tensile reinforcement the concrete element is also reinforced near the compressive face to help the concrete resist compression. The latter reinforcement is called compression steel. 双筋梁是指不仅有受拉筋，在受压区也配置钢筋协助混凝土承受压应力的混凝土构件。后面这种钢筋叫受压钢筋。 When the

36、 compression zone of a concrete is inadequate to resist the compressive moment (positive moment), extra reinforcement has to be provided if the architect limits the dimensions of the section. 当混凝土的受压区不足以承受压力矩（正力矩），且截面尺寸受限制，必须配置额外的钢筋。 An under-reinforced beam is one in which the tension capacity of t

37、he tensile reinforcement is smaller than the combined compression capacity of the concrete and the compression steel (under-reinforced at tensile face). 适筋梁是指受拉钢筋的抗拉强度低于混凝土与受压钢筋组合起来的抗压强度（在受拉区钢筋较少）。 When the reinforced concrete element is subject to increasing bending moment, the tension steel yields

38、 while the concrete does not reach its ultimate failure condition. 当这种钢筋混凝土构件承受增长了的弯矩时，受拉钢筋屈服而混凝土并没有达到临界失效状况。 As the tension steel yields and stretches, an under-reinforced concrete also yields in a ductile manner, exhibiting a large deformation and warning before its ultimate failure. In this case

39、the yield stress of the steel governs the design. 单筋梁是指只在受拉区混凝土构件中配置钢筋，并用受拉钢筋来抵御拉力的梁。当受拉钢筋屈服并延伸，少筋梁也发生延性屈服，在临界破坏前表现出大的变形和预警。在这种情况下，钢筋的屈服应力在设计中起控制作用。 An over-reinforced beam is one in which the tension capacity of the tension steel is greater than the combined compression capacity of the concrete and

40、 the compression steel (over-reinforced at tensile face). 超筋梁是指受拉钢筋的抗拉强度高于于混凝土与受压钢筋组合起来的抗压强度（在受拉区超筋） 。 So the over-reinforced concrete beam fails by crushing of the compressive-zone concrete and before the tension zone steel yields, which does not provide any warning before failure as the failure is

41、 instantaneous. 因此，超筋梁破坏时，在拉区钢筋屈服前，压区混凝土已经被压碎，破坏前没有预警，破坏是瞬间发生的。 A balanced-reinforced beam is one in which both the compressive and tensile zones reach yielding at the same imposed load on the beam, and the concrete will crush and the tensile steel will yield at the same time. 平衡配筋梁在同样的外加荷载作用下，压区和拉区

42、同时屈服，混凝土压碎和钢筋屈服发生在同一时间。 This design criterion is however as risky as over-reinforced concrete, because failure is sudden as the concrete crushes at the same time of the tensile steel yields, which gives a very little warning of distress in tension failure. 这样的设计标准和超筋混凝土结构一样危险，因为钢筋屈服的同时混凝土被压碎，破坏很突然，对

43、受拉破坏仅有很小的预警。 Steel-reinforced concrete moment-carrying elements should normally be designed to be under-reinforced so that users of the structure will receive warning of impending collapse. 钢筋混凝土受弯构件通常应设计为适筋构件，以便建筑物的使用者在面对即将到来的倒塌时接到预警。 （8）Can you translate the following terminology of beams? （8）你能翻译

44、下面的梁相关的术语吗？ singly reinforced beam doubly reinforced beam under-reinforced beam over-reinforced beam balanced-reinforced beam singly reinforced beam 单筋梁 doubly reinforced beam 双筋梁 under-reinforced beam 少筋梁 over-reinforced beam 超筋梁 balanced-reinforced beam 适筋梁Translate some important sentences 翻译句子 (

45、1) Plain concrete is strong in compression but very weak in tension. (2) Plain concrete, commonly known as concrete, is an intimate mixture of binding material, fine aggregate, coarse aggregate and water. (3) The composite material of steel and concrete now called R.C.C. acts as a structural member

46、and can resist tensile as well as compressive stresses very well.(4) 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. (5) Carbonatation of concrete along with chloride ingr

47、ess is amongst the chief reasons for the failure of reinforcement bars in concrete. Keys： (1)素混凝土抗压能力很强，但是抗拉能力不足。 (2)素混凝土，也就是人们所熟知的混凝土，是粘合料、细骨料、粗骨料和水的混合物。 (3)钢筋和混凝土的混合物也叫钢筋混凝土，是一种能很好地抗拉和抗压的结构构件。 (4)在建筑行业里，由混凝土承担压力和由钢筋承担拉力的钢筋混凝土截面几乎可以被做成任何形状和尺寸。 (5)混凝土碳化和氯离子的侵蚀是水泥中钢筋失效的主要原因。 Special difficulties 难点讲解

48、难点讲解 1 Without reinforcement, constructing modern structures with the concrete material would not be possible. 译文：没有钢筋，就不可能用混凝土材料建造现代结构。 （1）with可以表示“使用某种工具”“使用某种方法”。例如： In building construction, concrete usually is placed with hand-or power-operated drop bottom buckets. 在建筑施工中，混凝土通常用人工或者电力小推车浇筑。 （2）

49、with也可以表示“带着”。例如： Bricks are also produced in many different colors and with various finishes. 砖也可以烧成不同的颜色，具有不同的光洁度。 （3）with也可以表示“随着”。例如： With the invention of the transistor, electronics entered a new phase. 随着晶体管的发明， 电子技术进入了一个新的阶段。 2 The relative cross-sectional area of steel required for typical

50、reinforced concrete is usually quite small and varies from 1% for most beams and slabs to 6% for some columns. 译文：典型钢筋混凝土所需的钢筋的截面面积通常很小，这个量在大多数梁和板所需的1%到有些柱所需的6%之间变化。 vary from.to. 意思是“从到不等”“在到的范围内变化”。例如： The face diagonal can vary from a low 14 angle（reclining twill）to a 75 angle（steep twill）. 织物正面的

51、斜纹线可以在较小的角度14（缓斜纹）至75（急斜纹）之间变化。 3 So the “over-reinforced concrete” beam fails by crushing of the compressive-zone concrete and before the tension zone steel yields, which does not provide any warning before failure as the failure is instantaneous. 译文：所以“超筋梁”是在受拉区钢筋屈服前由于受压区混凝土压碎而失效。失效前并未有任何迹象，因为失效是瞬

52、间发生的。 （1）by可以表示“用某种方式”“用某种方法”。 例如： And offshore drilling is made possible by using huge quantities of gaseous nitrogen and oxygen to provide a livable atmosphere deep under water.用大量的氮气和氧气形成在深水中能够生活的环境，才有可能进行海底石油钻探。 （2）by还可以表示“按照”。例如： By the law of Universal Gravitation, all bodies attract each othe

53、r. 按照万有引力定律，一切物体都相互吸引。 （3）by还可以表示“所谓”。例如： By hPa we mean an international standardized pressure unit. 所谓百帕，是国际通用的表示气压的单位。Translation Skills 长句的分译与合译流畅表达 分译是翻译英语长句时常见的技巧。分译有助于梳理原文的层次和逻辑结构，有助于用符合汉语习惯的语言来组织译文。 在分译时，先将长句按意义拆分成相对较短的不同句子，分别理解拆分后的句子，然后将意义重新组合译出。按具体情形可分为顺译（逻辑意义顺序与汉语一致时）、逆译（逻辑意义顺序与汉语相反时）、拆译（

54、逻辑意义顺序与汉语完全不同时）。无论采用何种方法，应该把理解原文放在第一位。 【例1】It is desirable that design engineers complete the job of material analysis, selection and specification at the early stage of design rather than leave it to the production-design stage, where material changes may be made by others, possibly less knowledgea

55、ble about all of the function aspects of the products. 本句的逻辑意义顺序与汉语基本一致。首先对句子意义进行拆分： （1）Design engineers should complete the job of material analysis, selection and specification at the early stage of design.（设计工程师最好在设计的早期阶段就完成所有材料的分析、选择和规格确定等工作。） （2）Design engineers should not leave the job of mate

56、rial analysis, selection and specification to the production-design stage.（设计工程师不应该将材料的分析、选择和规格确定工作留到生产设计阶段。） （3）At the production-design stage, material changes may be designed by others.（生产设计阶段，材料的更换由他人负责。） （4）These people may possibly be less knowledgeable about all of the function aspects of the products .（这些人对产品功能的了解可能不如工程师。） 按顺序将拆分后的句子合译为： 设计工程师最好在设计的早期阶段就完成所有材料的分析、选择和规格确定等工作，而不是将这些工作留到生产设计阶段。因为在生产设计阶段，材料的更换由他人负责，这些人对产品功能的了解可能不如工程师。Writing Skills 英文摘要