土木毕业设计外文翻译.doc

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1、毕 业 设 计（论 文）外 文 参 考 资 料 及 译 文 译文题目： DESIGN OF REINFORCED CONCRETE STRUCTURES 学生姓名： 杨涛 学 号： 专 业： 土木工程 所在学院： 建筑工程学院 指导教师： 蒋跃南 职 称： 讲师 2014年 12月 31日原文：DESIGN OF REINFORCED CONCRETE STRUCTURES1. BASIC CONCERPTS AND CHARACERACTERISTICS OF REINFORCED CONCRETEPlain concrete is formed from hardened mixture

2、of cement, water , fine aggregate , coarse aggregate (crushed stone or gravel ) , air and often other admixtures . The plastic mix is placed and consolidated in the formwork, then cured to accelerate of the chemical hydration of hen cement mix and results in a hardened concrete. It is generally know

3、n that concrete has high compressive strength and low resistance to tension. Its tensile strength is approximately one-tenth of its compressive strength. Consequently, tensile reinforcement in the tension zone has to be provided to supplement the tensile strength of the reinforced concrete section.F

4、or example, a plain concrete beam under a uniformly distributed load q is shown in Fig . 1.1(a), when the distributed load increases and reaches a value q=1.37KN/m , the tensile region at the mid-span will be cracked and the beam will fail suddenly . A reinforced concrete beam if the same size but h

5、as to steel reinforcing bars (216) embedded at the bottom under a uniformly distributed load q is shown in Fig.1.1(b). The reinforcing bars take up the tension there after the concrete is cracked. When the load q is increased, the width of the cracks, the deflection and the stress of steel bars will

6、 increase . When the steel approaches the yielding stress y , the deflection and the cracked width are so large offering some warning that the compression zone . The failure load q=9.31KN/m, is approximately 6.8 times that for the plain concrete beam. Concrete and reinforcement can work together bec

7、ause there is a sufficiently strong bond between the two materials, there are no relative movements of the bars and the surrounding concrete cracking. The thermal expansion coefficients of the two materials are 1.210-5K-1 for steel and 1.010-51.510-5K-1 for concrete . Generally speaking, reinforced

8、structure possess following features :Durability .With the reinforcing steel protected by the concrete , reinforced concrete1.37kn/m6m200400(a)plain concrete beam9.31kn/m6m200400(b)Reinfoced concrete beam216Fig.1.1Plain concrete beam and reinforced concrete beamIs perhaps one of the most durable mat

9、erials for construction .It does not rot rust , and is not vulnerable to efflorescence . (2)Fire resistance .Both concrete an steel are not inflammable materials .They would not be affected by fire below the temperature of 200 when there is a moderate amount of concrete cover giving sufficient therm

10、al insulation to the embedded reinforcement bars.(3)High stiffness .Most reinforced concrete structures have comparatively large cross sections .As concrete has high modulus of elasticity, reinforced concrete structures are usually stiffer than structures of other materials, thus they are less prone

11、 to large deformations, This property also makes the reinforced concrete less adaptable to situations requiring certain flexibility, such as high-rise buildings under seismic load, and particular provisions have to be made if reinforced concrete is used.(4)Locally available resources. It is always p

12、ossible to make use of the local resources of labour and materials such as fine and coarse aggregates. Only cement and reinforcement need to be brought in from outside provinces.(5)Cost effective. Comparing with steel structures, reinforced concrete structures are cheaper.(6)Large dead mass, The den

13、sity of reinforced concrete may reach 24002500kg/m3.Compare with structures of other materials, reinforced concrete structures generally have a heavy dead mass. However, this may be not always disadvantageous, particularly for those structures which rely on heavy dead weight to maintain stability, s

14、uch as gravity dam and other retaining structure. The development and use of light weight aggregate have to a certain extent make concrete structure lighter.(7)Long curing period. It normally takes a curing period of 28 day under specified conditions for concrete to acquire its full nominal strength

15、. This makes the progress of reinforced concrete structure construction subject to seasonal climate. The development of factory prefabricated members and investment in metal formwork also reduce the consumption of timber formwork materials.(8)Easily cracked. Concrete is weak in tension and is easily

16、 cracked in the tension zone. Reinforcing bars are provided not to prevent the concrete from cracking but to take up the tensile force. So most of the reinforced concrete structure in service is behaving in a cracked state. This is an inherent is subjected to a compressive force before working load

17、is applied. Thus the compressed concrete can take up some tension from the load.2. HISTOEICAL DEVELPPMENT OF CONCRETE STRUCTUREAlthough concrete and its cementitious(volcanic) constituents, such as pozzolanic ash, have been used since the days of Greek, the Romans, and possibly earlier ancient civil

18、ization, the use of reinforced concrete for construction purpose is a relatively recent event, In 1801, F. Concrete published his statement of principles of construction, recognizing the weakness if concrete in tension, The beginning of reinforced concrete is generally attributed to Frenchman J. L.

19、Lambot, who in 1850 constructed, for the first time, a small boat with concrete for exhibition in the 1855 Worlds Fair in Paris. In England, W. B. Wilkinson registered a patent for reinforced concrete l=floor slab in 1854.J.Monier, a French gardener used metal frames as reinforcement to make garden

20、plant containers in 1867. Before 1870, Monier had taken a series of patents to make reinforced concrete pipes, slabs, and arches. But Monier had no knowledge of the working principle of this new material, he placed the reinforcement at the mid-depth of his wares. Then little construction was done in

21、 reinforced concrete. It is until 1887, when the German engineers Wayss and Bauschinger proposed to place the reinforcement in the tension zone, the use of reinforced concrete as a material of construction began to spread rapidly. In1906, C. A. P. Turner developed the first flat slab without beams.B

22、efore the early twenties of 20th century, reinforced concrete went through the initial stage of its development, Considerable progress occurred in the field such that by 1910 the German Committee for Reinforced Concrete, the Austrian Concrete Committee, the American Concrete Institute, and the Briti

23、sh Concrete Institute were established. Various structural elements, such as beams, slabs, columns, frames, arches, footings, etc. were developed using this material. However, the strength of concrete and that of reinforcing bars were still very low. The common strength of concrete at the beginning

24、of 20th century was about 15MPa in compression, and the tensile strength of steel bars was about 200MPa. The elements were designed along the allowable stresses which was an extension of the principles in strength of materials.By the late twenties, reinforced concrete entered a new stage of developm

25、ent. Many buildings, bridges, liquid containers, thin shells and prefabricated members of reinforced concrete were concrete were constructed by 1920. The era of linear and circular prestressing began. Reinforced concrete, because of its low cost and easy availability, has become the staple material

26、of construction all over the world. Up to now, the quality of concrete has been greatly improved and the range of its utility has been expanded. The design approach has also been innovative to giving the new role for reinforced concrete is to play in the world of construction.The concrete commonly u

27、sed today has a compressive strength of 2040MPa. For concrete used in pre-stressed concrete the compressive strength may be as high as 6080MPa. The reinforcing bars commonly used today has a tensile strength of 400MPa, and the ultimate tensile strength of prestressing wire may reach 15701860Pa. The

28、development of high strength concrete makes it possible for reinforced concrete to be used in high-rise buildings, off-shore structures, pressure vessels, etc. In order to reduce the dead weight of concrete structures, various kinds of light concrete have been developed with a density of 14001800kg/

29、m3. With a compressive strength of 50MPa, light weight concrete may be used in load bearing structures. One of the best examples is the gymnasium of the University of Illinois which has a span of 122m and is constructed of concrete with a density of 1700kg/m3. Another example is the two 20-story apa

30、rtment houses at the Xi-Bian-Men in Beijing. The walls of these two buildings are light weight concrete with a density of 1800kg/m3.The tallest reinforced concrete building in the world today is the 76-story Water Tower Building in Chicago with a height of 262m. The tallest reinforced concrete build

31、ing in China today is the 63-story International Trade Center in GuangZhou with a height a height of 200m. The tallest reinforced concrete construction in the world is the 549m high International Television Tower in Toronto, Canada. He prestressed concrete T-section simply supported beam bridge over

32、 the Yellow River in Luoyang has 67 spans and the standard span length is 50m.In the design of reinforced concrete structures, limit state design concept has replaced the old allowable stresses principle. Reliability analysis based on the probability theory has very recently been introduced putting

33、the limit state design on a sound theoretical foundation. Elastic-plastic analysis of continuous beams is established and is accepted in most of the design codes. Finite element analysis is extensively used in the design of reinforced concrete structures and non-linear behavior of concrete is taken

34、into consideration. Recent earthquake disasters prompted the research in the seismic resistant reinforced of concrete structures. Significant results have been accumulated.3. SPECIAL FEATURES OF THE COURSEReinforced concrete is a widely used material for construction. Hence, graduates of every civil

35、 engineering program must have, as a minimum requirement, a basic understanding of the fundamentals of reinforced concrete.The course of Reinforced Concrete Design requires the prerequisite of Engineering Mechanics, Strength of Materials, and some if not all, of Theory of Structures, In all these co

36、urses, with the exception of Strength of Materials to some extent, a structure is treated of in the abstract. For instance, in the theory of rigid frame analysis, all members have an abstract EI/l value, regardless of what the act value may be. But the theory of reinforced concrete is different, it

37、deals with specific materials, concrete and steel. The values of most parameters must be determined by experiments and can no more be regarded as some abstract. Additionally, due to the low tensile strength of concrete, the reinforced concrete members usually work with cracks, some of the parameters

38、 such as the elastic modulus I of concrete and the inertia I of section are variable with the loads.The theory of reinforced concrete is relatively young. Although great progress has been made, the theory is still empirical in nature in stead of rational. Many formulas can not be derived from a few

39、propositions, and may cause some difficulties for students. Besides, due to the difference in practice in different countries, most countries base their design methods on their own experience and experimental results. Consequently, what one learns in one country may be different in another country.

40、Besides, the theory is still in a stage of rapid development and is subjected to revision according to new findings from research. In China, the design code undergoes major revision in about every fifteen years and with minor revision in between. This book is based on the latest current code in Chin

41、a “Code for Design of Concrete Structures”(GB50010-2002). The students must keep in mind that this course can not give them the knowledge which is universally valid regardless of time and place, but the basic principles on which the current design method in the country is established.The desk calcul

42、ator has made calculations to a high degree of precision possible and easy. Students must not forget that concrete is a man-made material and a 10% consistency in quality is remarkably good. Reinforcing bad=rs are rolled in factory, yet variation is=n strength may be as high as 5%. Besides, the posi

43、tion of bars in the formwork may deviate from their design positions. In fact two figure accuracy is adequate for almost all the cases, rather than carrying the calculations to meaningless precision. The time and effort of the designer are better spent to find out where the tension may occur to resi

44、st it by placing reinforcement there.中文译文：钢筋混凝土结构设计一、钢筋混凝土基本概念和特点混凝土是指由水泥胶凝的水、细致聚合体、粗聚合物（碎石或沙砾）、空气、以及其他混合物的坚硬混合物。这种塑体在制作过程中，加水的水泥并混合然后晒干最终成为坚硬的混凝土。通常我们都知道混凝土有高抗压低抗拉的受力特性。其抗拉强度大概抗压强度的十分之一。所以，为了增加混凝土截面的抗拉强度必须增加受拉区间的受拉钢筋。例如，如图1.1（a）所示一段均布荷载梁，当均布荷载增大至q=1,37kn/m时，中部抗拉区域将会破坏并且梁会突然断裂。一段增加了2根钢筋（2 16）的加强梁受到均

45、布荷载q如图1.1（b）所示。当混凝土破坏时受拉钢筋承受其受到的原有。当承载力q增大，破坏程度、作用于钢筋上的偏心受压将会大。当钢筋接近纵向y方向的屈服强度时，很多偏移和破坏程度预兆梁将会塌落。梁的破坏是由于受压区域的混凝土破坏。破坏荷载q=9.31kn/m，是素混凝土梁的6.8倍。混凝土和钢筋可以同时起作用是因为在两种材料之间有足够的粘合力，在破坏之前钢筋和包裹混凝土没有相对位移。这两种材料的温度扩张系数钢材为1.210-5K-1 ，混凝土为1.010-5至1.510-5K-1。1.37kn/m6m200400(a)素混凝土梁9.31kn/m6m200400(b)钢筋混凝土梁216图1.1.

46、素混凝土梁和钢筋混凝土梁通常来说，钢筋混凝土结构具有以下特点：坚固耐用。受拉钢筋受到混凝土的保护，这种钢筋混凝土可能是是最耐用的建筑构造之一。它不会腐蚀和锈蚀，且不会被风化。耐火性强。混凝土和钢筋都不是可燃材料。当钢筋于混凝土的包裹下时，并不惧怕200以下的火焰。高硬度。大多数的钢筋混凝土构件具有相对较大的横截面。由于混凝土具有较大的弹性模量，钢筋混凝土通常比其他材料更加坚硬，因此更不容易发生形变。这个性质同样使得钢筋混凝土不适用于地形要求更加有弹性的地方，例如地震带中的高层建筑，以及对钢筋混凝土有特殊要求的地方。材料可在当地获得。可采用当地劳动力和材料，例如粗细集料。只有水泥和钢筋需要从他地

47、运输。造价低。相比于钢构件，钢筋混凝土构件更加便宜。大重量。纯钢构件可能达到24002500kg/m3。相较于其他材料构件钢筋混凝土构件通常具有很大的重量。无论如何，这可能是有利的，尤其对于那些需要较大重量来保持稳固的构造，例如重型水坝以及其他挡土墙构造。重型集料的运用和发展使得混凝土构件将会越来越广泛。长养护期。通常要用28天使得混凝土达到最大强度。这使得钢筋混凝土构造建设周期适应于季节性气候。工厂可以预先减少损失。 同时也可提前减少金属和木材的投资和损失。易于破坏。混凝土受拉能力弱并且在受拉区域容易受到破坏。钢筋可以与放其受拉破坏并提升其受拉承载力。所以大部分钢筋混凝土构造都是破坏在指定区

48、域。这是一种钢筋混凝土的天生缺陷。预应力混凝土构造在受到荷载前可事先施加一定的力。这样预应力混凝土就可以承载更大的荷载。二、混凝土结构的发展历史尽管水泥和水泥构成物（例如火山灰）的应用可能早于古希腊和古罗马文明，但钢筋混凝土用于建筑还是一个较新的事件。在1801年，F.Coignet 发表了他的建筑原理声明，指出了混凝土在受拉条件下的拖点。钢筋混凝土首次被广泛承认是在1850年被一个名叫J.LLambot的法国人，1855年一小船混凝土在巴黎世界展览会上被展出。1854年W.B.Wilkinson在英国得到了钢筋混凝土楼板的专利。1854年一个名叫J.Monier的法国园丁运用金属骨架制作了植物支架。1870之前，Monier连续获得了钢筋混凝土管、板和拱的专利证书。但是Monier没有这种新材料工作原理方面的知识，他将钢筋加入了他的制造品中。然后少量的建筑开始使用钢筋混凝土。1887年以前，德国工程师Wayss和Bauschinger建议在受拉区域加入钢筋，在建筑中使用钢筋混凝土作为材料开始快速蔓延开来。在1906年，C.A.P.Turn