混凝土毕业设计外文翻译--保护,预防,修复,改造和升级

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混凝土毕业设计外文翻译--保护,预防,修复,改造和升级

外文文献翻译Protection,prevention,repair,renovation and upgrading（摘自《Management of Deteriorating Concrete Structures》Chapter 7作者George Somerville ）7.1 IntroductionThe need to repair concrete structure is not new. Much of the early work involved making good via patch repairs and crack filling, for aesthetic and serviceability reasons[7.1]. As the concrete infrastructure of the mid-20th century matured, there was also a demand to strengthen or upgrade to meet changes in use or increase in loadings. The need to treat cases of corrosion emerged in the 1950s with post-war prefabricated reinforced concrete housing,and many of the references to Chapter 2 detail examples of corrosion in highway structures as the use of de-icing salts increased rapidly in the early 1960s.Reference[7.2] gives some details of this ,and reference [7.3] is a detailed review of the situation in the UK and France with regard to post-tesioned concrete bridges.As durability concerns became more widespread, and consequences of failure more critical, repair became a growth industry, and options available on the market increased significantly in term of principles and approaches, and the individual solutions within each basic approach. This taining over 200 short papers on all aspects of the problem.The literature is full of individual case studies, describing what has been physically done and giving some reasons for selecting a particular option; it is often diffcult to draw general conclusions from these. Such articles, which are also helpful since they provide website addressers,appear most frequently in concrete-related journals such as Concrete from the Concrete Society in the UK. In North America, the various journals of the American Concrete Institute (ACI) do a similar job, and focus on repair is provided by the International Concrete Repair Institute (ICRI),which publishs a bimonthly Bulletin, and whose website gives details of available publications in the USA; generally, these are either guidance documents, or complications of articles on particular topics.There are aslo guidance documents available on individual repair, protection and upgrading methods, which explain the principles involved and are strong on the “how to …” aspects of the problem. Some examples of these can be obtained from the ICRIwebsite for North America, and reference[7.4-7.9] are similar publications available from the Concrete Society in the UK. The Concrete Society portfolio is augmented by other reports on test methods and diagnosis,and on how to enhance durability in new constructions; Technical Report 61 [7.10] is an example of the latter, where much of the detailed information is transferable to the repair and renovation situation. The Concrete RepairAssocication in the UK also has a website.The above brief rewiew is intended to show that there is quite a lot of information available on repair and renovation methods and also to indicate the nature of that information. It can become dated quite quickly however, as the technology is improved and new techniques are introduced. Moreover,, the nature and format of the information make it difficult to compare the technical and economic merits of alternative approaches- essential information to the owner when making a choice. This situation is now changing, with serious attempts being made to develop a systematic scientific basis for classifying repair and renovation methods, supported by sound specification and test methods. The emergence of EN 1504 is a prime example of that, and will be referred to strongly in later sections of this chapter.The final major missing link from the data bases is the lack of indepth feedback on real performation in the field over relevant periods of time. How does this compare with claims and expectations? Again this is changing, as typified by Figures 2.13-2.16 ,taken from the paper by Tilly [7.11]. Tilly's paper comes from the activities of a European network CONREPNET, which has examined well over 100 case studies in some detail and, apart from providing field data, has forced on developing criteria to permit alterative options to be evaluated to a common base. This information will also be used extensively later in this chapter.Repair and renovation is a huge subject, deserving several books in its own right.This book is about assessment, management and maintenance, and repair is an integral part of that. The emphasis in this chapter is on how it fits into the overall scheme of things, in moving forward from the assessment phase to taking effective action in selecting optimum solutions. This approach leads to the following sequence of subsection.7.2 Performance requirements for repaired structures7.3 Classification of protection, repair,renovation and upgrading options7.4 Performance requirements for repair and remedial measures7.5 Engineering specifications7.6 Moving towards the selection process7.7 Performance of repairs in sevice7.8 Timing of an intervention7.9 Selection a repair option-general7.10 The role of EN 1504 in selection7.11 Selecting a repair option in practice7.12 Concluding remarks Appendix 7.1 and 7.2 Reference7.2 Performance requirements for repaired structuresIn simple terms, the performance requirements for repaired structures are no different from those for new construction. Structurally, the focus will be on the factors listed in Table 4.12. Progressive assessment will have led to a performance time graph, such as that in Figure 3.13, for all relevant Table 4.12 factors. This paints a picture of how the present condition relates both to the performance levels provided in the original design and to the owner's perception of what constitutes minimum acceptable performance, bearing in mind that much more is now known about the structure (the Table 6.2 issue).Complicating the situation is the fact different owners may wish to manage the rehabilitation process differently. Figure 3.3 shows two viable options emanating from the asset management procedures associated with bridge in the UK . The different strategies involved intervention on different timescales, and,most probably, different solutions. Some owners may also wish to take a conservative approach,involving early preventative measures. There are no definitive general rules here, but a need to be aware of what the options are , linked to confidence in their effectiveness.In moving forward, however, it is essential to be clear about the required performance levels. While the basic structural factors in Table 4.12 will remain, there are broader strategies issues involved, some non-technical,which will influence the course which individual owners may choose to follow. Different owners will have different strategic goals, depending, for example, on:•type of ownership – whether private or public sector;•changing statutory requirements;•the type of structure and its function;•future plans for the structure, independent of its current physicall state, due, say, to – a possible change in use;-- improved performance requirements arising from higher user expectations;-- increases in imposed loadings;• a greater emphasis on whole life costing, linked to budgetary plans;•s desire for improved sustainability.In a follow-up project to CONTECVET, a group of parters containing a high proportion of owners from Spain, Sweden and the UK, set out to establish a strategy for the maitenance and rehabilition of concrete structures. As part of this project, acronym REHABCON, a list of general performance requirements was developed. Table 7.1, taken from a REHABCON deliverable [7.12] ,givesdetails. While the majority of the requirements relate to the structure as a whole, some also relate to the selected rehabilitation option and to the renovation process itself.Table 7.1 General performance requirements for rehabilitated structures.Rehabcon [7.12]General performance requirements__________________________________________________________________ Structural safety Ultimate limit state design (same expectations as for newstructures)•Strength•Stability•Robustness•Fatigue•Fire resistance•Earthquake resistanceServiceability Serviceability limit state design (same expectations as fornew structures)•Deformation•Displacement•Vibrations•Watertightness•Slip resistance/roughness•Drainage•Visibility during inclement weather•Comfort/convenience to userOperation and function•Availability, functionability•Minimisation of downtime. While this is important for a rehabilitated structure, it is also important to minimise inconvenience to users during the rehabilitation action,i.e,low low impact on users during operation, maintenance and repair.Aesthetics•Inspectability•Colour•Texture of surface•Durability of aesthetics•Safe-lookingSustainabilityand environmentalfactors•Materials for rehabilitation works tobe sustainable, and environmentally friendlyduring•Manufacture•Construction works•Use•Damage•Demolition•Impact on recycling and reuse•Deposition•Acoustics, noise control•Energy consumption•Harmful effects, such as spillage, leakage, dust or the emission of toxic fumes, either spontaneously or due to situiations such as fire, both duringthe rehabilitation works and afterwardsHeath andSafety•Public safety•Health for humans and nature during all phases in the life-cycle•Evacuation, emergency escape routesDurability•Durability of the original structure and the rehabilitated parts of the structure. Dependability•Reliability of the repair methods•Maitainability•Maintenance supportabilityFlexibility•Ensure that it is possible to meet future requirementEconomy•Reduce or limit whole life costs•Operational costs•Maintenance, repair and rehabilitation costs•Improvement/strengthening costs•Demolition and deposition costs•User cost•Limit loss of income due to insufficient functionality etc Cultureheritage•Structure having cultural or historic value require special treatment保护，预防，修复，改造和升级（摘自《混凝土结构腐蚀恶化的管理》第7章作者乔治·萨默维尔）7.1简介混凝土结构需要修复对我们来说并不陌生。

混凝土工程中英文(个人整理)

混凝土工程concrete works一、材料袋装水泥bagged cement散装水泥bulk cement砂sand骨料aggregate商品混凝土commercial concrete现浇混凝土concrete-in-situ预制混凝土precast concrete预埋件embedment（fit 安装）外加剂admixtures抗渗混凝土waterproofing concrete 石场aggregate quarry垫块spacer二、施工机械及工具搅拌机mixer振动器vibrator电动振动器electrical vibrator 振动棒vibrator bar抹子（steel wood）trowel磨光机glasser混凝土泵送机concrete pump 橡胶圈rubber ring夹子clip混凝土运输车mixer truck自动搅拌站auto-batching plant 输送机conveyor塔吊tower crane汽车式吊车motor crane铲子shovel水枪jetting water橡胶轮胎rubber tires布袋cloth-bags塑料水管plastic tubes喷水雾spray water fog三、构件及其他专业名称截面尺寸section size（section dimension）混凝土梁concrete girder简支梁simple supported beam挑梁cantilever beam悬挑板cantilevered slab檐板eaves board封口梁joint girder翻梁upstand beam楼板floor slab空调板AC board飘窗bay window（suspending window）振捣vibration串筒 a chain of funnels混凝土施工缝concrete joint水灰比ratio of water and cement砂率sand ratio大体积混凝土large quantity of pouring混凝土配合比concrete mixture rate混凝土硬化hardening of concrete(in a hardening process 硬化中)规定时间regulated period质保文件quality assurance program设计强度design strength永久工程permanent works临时工程temporary works四、质量控制及检测不符合规格的non-standard有机物organic matters粘土clay含水率moisture content（water content）中心线central line安定性soundness （good soundness 优良的安定性）坍落度slump (the concrete with 18mm±20mm slump)混凝土养护concrete curing标养混凝土试件standard curing concrete test sample 同条件混凝土试件field-cure specimen收缩shrinkage初凝时间initial setting time终凝时间final setting time成品保护finished product protection混凝土试件concrete cube偏心受压eccentric pressing保护层concrete cover孔洞hole裂缝crack蜂窝honeycomb五、句子1，Usually we control the cement within 2% 我们将水泥的误差控制在2%2，Are there any pipe clogging happened during the concreting?浇筑混凝土中有堵管现象吗？3，Will the pipe be worn out very fast？管道磨损很快吗？4，T his embedment is fixed at 1500mm from the floor and 350mm from the left edge of the column. Would you measure the dimension by this meter?预埋件的位置在地面上1500mm，离柱边350mm。

混凝土英文论文

Development of Green High Performance Concrete for SustainableDevelopment0706121 29 刘海庆Abstract: With the fast development of society and economy an important factor that affects social and economicdevelopment is environmental pollution. In face of reduction of the natural resources and the growing problem ofenvironmental pollution, the ordinary concrete has not been fit with the need of the social economy; the perfor-mances of concrete are required improvement. So the development of the concrete materials is generally considered with environmental protection, energy conservation, resource saving and the green high performance concrete is developed. The green high performance concrete that is developed in recent years is a new building material. The concept and features of green high performance concrete are introduced, then the categories and current application of it are analyzed and exist problems are proposed, finally it is concluded that the development of green high per-formance concrete is the only way for the sustainable development of the concrete materials.Keywords:green high performance concrete; environmental pollution; sustainable development CLC: TU528 Document code: A Article ID: 1672-2132(2010)Suppl.-0432-040 IntroductionConcrete is the most widely used and the greatest amount of building materials in the con-struction area. However, extensive use of concrete has destroyed unprecedented natural resources so that resources and energy appear crisis. Concrete in the 21st.century not only meets with the re-quirements of the structure, but also minimizes asmuch as possible the damage to the ecological envi-ronment to the need of sustainable development.So, developing the green high performance con-crete is the need of the sustainable develop-ment.1 Connotation and features of green high performance concretenWu Zongwei, academician of Chinese academy of engineering, first proposed the concept of con-crete and he pointed out the green high perfor-mance concrete was the direction of concrete devel-opment. Researchers consider the green high performance concrete should follow conditions as follows:(1) Cement used must be green cement. Sand and stone should be exploited orderly and withoutdamaging the environment.(2) Cement consumption should be saved tothe greatest extent in order to reduce by-products during the course of producing cement, for exam-ple, CO2, SO2, and NO2and so on.(3) Agricultural and industrial waste residueprocessed should be mixed more, such as, ground-ed slag, high-quality fly ash, silica fume and rice husk, to reduce cement, protect environment and improve concrete durability.(4) Industrial waste liquid should be used a lot, especially; water reducing agent made by black paper waste liquid and other composite addi-tive developed should be mixed to help dealing with other liquid.(5) Concrete should be mixed in the mixing station to reduce waste, dust and waster water of mixing concrete in site and waste and water recy-cling should be strengthened.(6) Through enhancing the strength, reduc-ing cross-sectional area or volume of structure, re-ducing concrete volume, cement, sand and stone can be saved. By improving durability of concrete,service life of structure can be lengthened and re-pair and reconstruction cost are further saved andthe indiscriminate use of natural resources will be reduced.(7) A lot of demolition waste should be recy-cled and recycled aggregate concrete should be de-veloped.The concept of green high performance con-crete is to strengthen people′s green awareness and to play an important role of energy saving and en-vironmental protection. It is concluded that the de-velopment of green high performance concrete is the only way for the sustainable development of concrete.2 Classification of the green high performance concrete2.1 Ecological environment-friendly concreteTo meet with the requirements of high strength and high durability, traditional concrete is always in pursuit of its compactness, which will cause concrete structures (lots of buildings and rigid pavement and so on) lack of permeability and permeability, exacerbate urban heat island effect,deteriorate human living environment. So rainwa-ter can not penetrate so that it lowers ground-wa-ter table in the city and affects growth of the sur-face plant, in a result, causes urban ecological sys-tem disorder. Because concrete color is gray, living space built in concrete gives a rough, hard, cold,dark feeling. So it is concluded that the develop-ment of ecological environment-friendly concrete is the only way to solve these problems. Another, e-cological environment-friendly concrete can be di-vided into plant concrete and water-permeability concrete according to different functions.2.2 Recycled aggregate concreteConcrete from the old buildings or structures can be divided into coarse and fine aggregate through breaking and this aggregate take place of some sand and gravel. So this is considered as re-cycled aggregate concrete. The use of recycled ag-gregate has been viewed as one of main measures in the development of green concrete.2.3 High-volume fly ash high performance con-creteFly ash mixed can improve concrete’s strength, impermeability and frost resistance,lower shrinkage; inhibit the effect of the alkali-ag-gregate reaction. High performance concrete which is mixed a great deal of fly ash and the morphologi-cal effects, micro-aggregate effects, volcanic ash effects of fly ash are used fully will lead to greater economic and environmental benefits.2.4 Environmentally mitigatable concrete(1) Environment-protecting concrete: the dif-ferences in composition between this concrete and traditional concrete are that a lot of solid waste,industrial waste residue, waste brick, concrete and solid rubbish and so on and additive produced through industrial waste liquid are mixed by taking certain technical measures to achieve all kinds of waste recycling and reduce environment pollution.(2) Energy-saving concrete: high temperature calcinations siliceous materials (clay or shale) and calcium raw material are needed in the course of ce-ment production, which will consume a large amount of energy. If concrete are prepared through non-burned cement, energy consumption can be reduced significantly.(3) Self-compacting concrete: self-compacting concrete is vibrated and compacted through self-weight. Because of this concrete has sufficient co-hesion so as to ensure disengagement in theprocess of pouring, a large amount of powder are required.3 Engineering application of green high performance concreteThe history of green high performance con-crete is not long, but it has obvious advantages and is paid attention to at home and abroad. Because concrete has been used widely as structural materi-al to date, appearance of green high performance concrete will become the main building structure materials in the 21st.century. Concrete strength in Chicago′s 311 South-walker Building in America with 295m height and 71 layers was C95. 40 mil-lion m3high performance concrete was used in both anchor piers of Akashi Kaikyo Bridge which was the longest suspension bridge at that time.The use of high green performance concretewas started late in China, especially the serious de-fects of the overpass in the Beijing and Tianjin re-gion arouse great concern in the engineering area.Research and application of green high perfor-mance concrete are increasing little by little.C80 high performance concrete are used in high-rise buildings and Jingan Center Building in Shang-hai.4 Existing problems of green high performance concrete4.1 Cost issuesThe cost of concrete is increased by 50% or more because used raw materials, the production and management level and production lines are raised. For example, collecting and preparing re-cycling aggregate must cost a certain machinery and equipment and manpower for recycled con-crete. From the point of economic indicators, the production of recycled aggregate is few profits, no profit, even deficit. If the production of recycled aggregate maintains a certain profit, its retail price will inevitably higher than the natural aggregate.Therefore, it is difficult to be accepted by users.4.2 Early crackingIn recent years cracking of concrete has be-come a hot topic at home and abroad and high per-formance concrete is no exception. That is, crackof concrete is very common. Many factors that in-fluence early cracking of concrete are as follows:self-shrinkage, drying shrinkage, earl y elastic modulus, tensile strength, ultimate tensile strain,creep, water evaporation rate, structural con-straint degree and so on.4.3 Mix problemThe same absolute volume is used with con-ventional concrete. After mixes of various compo-nents are determined, the performance require-ments are proved through experiments. The mix design of green high performance concrete is more difficult than that of common concrete. Comparing with mix design of conventional concrete, the mix design parameters of green high performance con-crete are smaller, such as, less than 0.4~0.42 water-cement ratio, less than 25mm the largest stone diameter (less than 20 mm or even 15 mm),2.6~3.0 sand fineness modulus, 42.5 concretes trength grade (ISO). So mix design will be sim-plified.5 ConclusionThe research of the green high performance technology in China is still in primary stage and the current research is not enough to conclude the laws that directly guide production. So the research and development of green high performance concrete should be increased greatly andquality standards and production specifications should be drawn up.In a word, we should attach great importance to green issues of concrete because these are related to our human survival and development. Through constant exploration and research, it is firmly be-lieved that the green high performance concrete is the only way for the sustainable development of the concrete materials.Reference:[1] CEB-FIP. Environment Design [R]. Lausanne: [s.n.],2004.[2]Malhotra V M. Introduction: Sustainable develop-ment and concrete technology [J].Concrete interna-tional,2002, 24(7):22.[3]吴中伟.绿色高性能混凝土——混凝土的发展方向[J].混凝土与水泥制品,1998,(1):3-6.[4]鄢朝勇.混凝土材料的可持续发展与粉煤灰绿色高性能混凝土[J].国外建材科技,2005,(4):5-7.[5] 王立久,汪振双,赵善宇.绿色生态混凝土技术的研究现状与发展[J].混凝土. 2009,(7):1-3.[6] Kumar M P. Reducing the environmental impact of concrete [J]. Concrete International,2001, 23(10):61-66.[7] Kumar M P. Greening of the concrete industry for sustainable development [J]. ConcreteInternational,2002, 24(7):23-28.[8] 王淑萍,王思远,张春,等.高性能混凝土的研究现状和发展应用[J].北方交通,2007,(4):47-50.[9]周士琼,李益进,尹健,等.复合超细粉煤灰与特种混凝土技术的开发与应用[J].铁道科学与工程学报,2004,(2):39-45.。

土木工程专业钢筋混凝土结构设计毕业论文外文文献翻译及原文

毕业设计（论文）外文文献翻译文献、资料中文题目：钢筋混凝土结构设计文献、资料英文题目：DESIGN OF REINFORCED CONCRETE STRUCTURES 文献、资料来源：文献、资料发表（出版）日期：院（部）：专业：土木工程班级：姓名：学号：指导教师：翻译日期： 2017.02.14毕业设计（论文）外文参考资料及译文译文题目：DESIGN OF REINFORCED CONCRETE STRUCTURES原文：DESIGN OF REINFORCED CONCRETESTRUCTURES1. BASIC CONCERPTS AND CHARACERACTERISTICS OF REINFORCED CONCRETEPlain concrete is formed from hardened mixture of cement, water , fine aggregate , coarse aggregate (crushed stone or gravel ) , air and often other admixtures . The plastic mix is placed and consolidated in the formwork, then cured to accelerate of the chemical hydration of hen cement mix and results in a hardened concrete. It is generally known that concrete has high compressive strength and low resistance to tension. Its tensile strength is approximatelyone-tenth of its compressive strength. Consequently, tensile reinforcement in the tension zone has to be provided to supplement the tensile strength of the reinforced concrete section.For example, a plain concrete beam under a uniformly distributed load q is shown in Fig .1.1(a), when the distributed load increases and reaches a value q=1.37KN/m , the tensile region at the mid-span will be cracked and the beam will fail suddenly . A reinforced concrete beam if the same size but has to steel reinforcing bars (2φ16) embedded at the bottom under a uniformly distributed load q is shown in Fig.1.1(b). The reinforcing bars take up the tension there after the concrete is cracked. When the load q is increased, the width of the cracks, the deflection and thestress of steel bars will increase . When the steel approaches the yielding stress ƒy , thedeflection and the cracked width are so large offering some warning that the compression zone . The failure load q=9.31KN/m, is approximately 6.8 times that for the plain concrete beam.Concrete and reinforcement can work together because there is a sufficiently strong bond between the two materials, there are no relative movements of the bars and the surrounding concrete cracking. The thermal expansion coefficients of the two materials are 1.2×10-5K-1 for steel and 1.0×10-5~1.5×10-5K-1 for concrete .Generally speaking, reinforced structure possess following features :Durability .With the reinforcing steel protected by the concrete , reinforced concreteFig.1.1Plain concrete beam and reinforced concrete beamIs perhaps one of the most durable materials for construction .It does not rot rust , and is not vulnerable to efflorescence .(2)Fire resistance .Both concrete an steel are not inflammable materials .They would not be affected by fire below the temperature of 200℃when there is a moderate amount of concrete cover giving sufficient thermal insulation to the embedded reinforcement bars.(3)High stiffness .Most reinforced concrete structures have comparatively large cross sections .As concrete has high modulus of elasticity, reinforced concrete structures are usuallystiffer than structures of other materials, thus they are less prone to large deformations, This property also makes the reinforced concrete less adaptable to situations requiring certainflexibility, such as high-rise buildings under seismic load, and particular provisions have to be made if reinforced concrete is used.(b)Reinfoced concrete beam(4)Locally available resources. It is always possible to make use of the local resources of labour and materials such as fine and coarse aggregates. Only cement and reinforcement need to be brought in from outside provinces.(5)Cost effective. Comparing with steel structures, reinforced concrete structures are cheaper.(6)Large dead mass, The density of reinforced concrete may reach2400~2500kg/pare with structures of other materials, reinforced concrete structures generally have a heavy dead mass. However, this may be not always disadvantageous, particularly for those structures which rely on heavy dead weight to maintain stability, such as gravity dam and other retaining structure. The development and use of light weight aggregate have to a certain extent make concrete structure lighter.(7)Long curing period.. It normally takes a curing period of 28 day under specified conditions for concrete to acquire its full nominal strength. This makes the progress of reinforced concrete structure construction subject to seasonal climate. The development of factory prefabricated members and investment in metal formwork also reduce the consumption of timber formwork materials.(8)Easily cracked. Concrete is weak in tension and is easily cracked in the tension zone. Reinforcing bars are provided not to prevent the concrete from cracking but to take up the tensile force. So most of the reinforced concrete structure in service is behaving in a cracked state. This is an inherent is subjected to a compressive force before working load is applied. Thus the compressed concrete can take up some tension from the load.2. HISTOEICAL DEVELPPMENT OF CONCRETE STRUCTUREAlthough concrete and its cementitious(volcanic) constituents, such as pozzolanic ash, have been used since the days of Greek, the Romans, and possibly earlier ancient civilization, the use of reinforced concrete for construction purpose is a relatively recent event, In 1801, F. Concrete published his statement of principles of construction, recognizing the weakness if concrete in tension, The beginning of reinforced concrete is generally attributed to Frenchman J. L. Lambot, who in 1850 constructed, for the first time, a small boat with concrete for exhibition in the 1855 World’s Fair in Paris. In England, W. B. Wilkinson registered a patent for reinforced concrete l=floor slab in 1854.J.Monier, a French gardener used metal frames as reinforcement to make garden plant containers in 1867. Before 1870, Monier had taken a series of patents to make reinforcedconcrete pipes, slabs, and arches. But Monier had no knowledge of the working principle of this new material, he placed the reinforcement at the mid-depth of his wares. Then little construction was done in reinforced concrete. It is until 1887, when the German engineers Wayss and Bauschinger proposed to place the reinforcement in the tension zone, the use of reinforced concrete as a material of construction began to spread rapidly. In1906, C. A. P. Turner developed the first flat slab without beams.Before the early twenties of 20th century, reinforced concrete went through the initial stage of its development, Considerable progress occurred in the field such that by 1910 the German Committee for Reinforced Concrete, the Austrian Concrete Committee, the American Concrete Institute, and the British Concrete Institute were established. Various structural elements, such as beams, slabs, columns, frames, arches, footings, etc. were developed using this material. However, the strength of concrete and that of reinforcing bars were still very low. The common strength of concrete at the beginning of 20th century was about 15MPa in compression, and the tensile strength of steel bars was about 200MPa. The elements were designed along the allowable stresses which was an extension of the principles in strength of materials.By the late twenties, reinforced concrete entered a new stage of development. Many buildings, bridges, liquid containers, thin shells and prefabricated members of reinforced concrete were concrete were constructed by 1920. The era of linear and circular prestressing began.. Reinforced concrete, because of its low cost and easy availability, has become the staple material of construction all over the world. Up to now, the quality of concrete has been greatly improved and the range of its utility has been expanded. The design approach has also been innovative to giving the new role for reinforced concrete is to play in the world of construction.The concrete commonly used today has a compressive strength of 20~40MPa. For concrete used in pre-stressed concrete the compressive strength may be as high as 60~80MPa. The reinforcing bars commonly used today has a tensile strength of 400MPa, and the ultimate tensile strength of prestressing wire may reach 1570~1860Pa. The development of high strength concrete makes it possible for reinforced concrete to be used in high-rise buildings, off-shore structures, pressure vessels, etc. In order to reduce the dead weight of concrete structures, various kinds of light concrete have been developed with a density of 1400~1800kg/m3. With a compressive strength of 50MPa, light weight concrete may be used in load bearing structures. One of the best examples is the gymnasium of the University of Illinois which has a span of 122m and is constructed of concrete with a density of 1700kg/m3. Another example is the two 20-story apartment houses at the Xi-Bian-Men in Beijing. The walls of these two buildings are light weight concrete with a density of 1800kg/m3.The tallest reinforced concrete building in the world today is the 76-story Water Tower Building in Chicago with a height of 262m. The tallest reinforced concrete building in China today is the 63-story International Trade Center in GuangZhou with a height a height of 200m. The tallest reinforced concrete construction in the world is the 549m high International Television Tower in Toronto, Canada. He prestressed concrete T-section simply supported beam bridge over the Yellow River in Luoyang has 67 spans and the standard span length is 50m.In the design of reinforced concrete structures, limit state design concept has replaced the old allowable stresses principle. Reliability analysis based on the probability theory has very recently been introduced putting the limit state design on a sound theoretical foundation. Elastic-plastic analysis of continuous beams is established and is accepted in most of the design codes. Finite element analysis is extensively used in the design of reinforced concrete structures and non-linear behavior of concrete is taken into consideration. Recent earthquake disasters prompted the research in the seismic resistant reinforced of concrete structures. Significant results have been accumulated.3. SPECIAL FEATURES OF THE COURSEReinforced concrete is a widely used material for construction. Hence, graduates of every civil engineering program must have, as a minimum requirement, a basic understanding of the fundamentals of reinforced concrete.The course of Reinforced Concrete Design requires the prerequisite of Engineering Mechanics, Strength of Materials, and some if not all, of Theory of Structures, In all these courses, with the exception of Strength of Materials to some extent, a structure is treated of in the abstract. For instance, in the theory of rigid frame analysis, all members have an abstract EI/l value, regardless of what the act value may be. But the theory of reinforced concrete is different, it deals with specific materials, concrete and steel. The values of most parameters must be determined by experiments and can no more be regarded as some abstract. Additionally, due to the low tensile strength of concrete, the reinforced concrete members usually work with cracks, some of the parameters such as the elastic modulus I of concrete and the inertia I of section are variable with the loads.The theory of reinforced concrete is relatively young. Although great progress has been made, the theory is still empirical in nature in stead of rational. Many formulas can not be derived from a few propositions, and may cause some difficulties for students. Besides, due to the difference in practice in different countries, most countries base their design methods on their own experience and experimental results. Consequently, what one learns in one country may be different in another country. Besides, the theory is still in a stage of rapid。

土木工程专业外语混凝土含翻译

4 Where fresh concrete is placed on hardened concrete, a good bond must be developed.5 The temperature of fresh concrete must be controlled from the time of mixing through final placement, and protected after placement.。

to avoid segregation.Selection of the most appropriate technique for economy depends on jobsite conditions, especially project size, equipment, and the contractor’s experience.In building construction，power-operated buggies; drop bottom buckets with a inclined chutes; flexible and rigid pipe by pumping;which either dry materials and water are sprayed separately or mixed concrete is shot against the forms; and for underwater placing, tremie chutes (closed flexible tubes).side-dump cars on narrow-gageFor pavement, concrete may be placed by bucket from the swinging boom of a paving mixer, directly by dump truck or mixer truck, or7 Even within the specified limits on slump and water-cementitious materials ratio, excess water must be avoided.In this context, excess water is presented for the conditions of placing if evidence of water rise (vertical segregation) or water flow (horizontal segregation) occurs.Excess water also tends to aggravate surface defects by increasedleakage through form openings. The result may be honeycomb, variations in color, or soft spots at the surface.8 In vertical formwork, water rise causes weak planes between each layer deposited. In addition to the deleterious structural effect, such planes, when hardened, contain voids which water may pass through.9 In horizontal elements, such as floor slabs, excess water rises and strength, low high and generallypoor quality.10 The purpose of consolidation is to eliminate voids of air and to ensure intimate complete contact of the concrete with the surfaces of the forms and the reinforcement.Intense vibration, however, may also reduce the volume of desirable entrained air; but this reduction can be compensated by adjustment of the mix proportions11 Powered internal vibrators are usually used to achieve consolidation. For thin slabs, however, high-quality, low-slump concrete can be effectively consolidated, without excess water, by mechanical surface vibrators.For precast elements in rigid external vibration is highly effective. External vibration is also effective with in-place forms, but should not be used unless the formwork is for theimpact of the vibrator.12 Except in certain paving operations, vibration of the reinforcement should be it is effective, thevertical rebars passing into partly set concrete below may be harmful.Note, however, that re-vibration of concrete before the final set, under controlled conditions, can improve concrete strength markedly and reduce surface voids.This technique is too difficult to control for general use on field-cast vertical elements, but it is very effective in finishing slabs with powered vibrating equipment.13 The interior of columns is usually congested; it contains a large volume of reinforcing steel compared with the volume of concrete, and has a large height compared with its cross-sectional dimensions.Therefore, though columns should be continuously cast, the concrete should be placed in 2-to 4-ft-deep increments and consolidated with internal vibrators. These should be lifted after each increment has been vibrated.If delay occurs in concrete supply before a beenWhen the remainder of the column isportion slightly.14 In all columns and reinforced narrow walls, concrete placing should begin with 2 to 4 inches of grout. Otherwise, loose stone will collect at the bottom, resulting in the formation of honeycomb. This grout should be proportioned for about the same slump as the concrete or slightly more, but at the same or lower water-cementitious material ratio.the same proportions of butWhen concrete is placed for walls,the only practicable means to avoid segregation is to place no more than a 24-in layer in one pass. Each layer should be vibrated separately and kept nearly level.15 For walls deeper than 4 ft, concrete should be placed through vertical. The concrete should not fall free more than 4 ft or segregation will occur, with the coarse aggregate ricocheting off thelayers after the initial layer should be penetrated by.can be beneficial (re-vibration), but control under variable jobsite conditions is too uncertain for recommendation of this practice for general use.16 The results of poor placement in walls are frequently observed:slope layer lines; honeycombs, leaking, if water is present; and, if cores are taken at successive heights, up to a 50% reduction in strength from bottom to top. Some precautions necessary to avoid these ill effects are:17 Do not move concrete laterally with vibrators18 For deep, long walls, reduce the slump for upper layers 2 to 3 in below the slump for the starting layer.19 On any placing of layers, vibrate the concrete20 Concrete should be inspected for the owner before, during, and after casting. Before concrete is placed, the formwork must be free of ice and debris and properly coated with bond-breaker oil.The rebars must be in place, properly supported to bear any traffic they will receive during concrete placing.inserts, and other items to be embedded must be inConstruction personnel should be available, usually carpenters, bar placers and other trades, if piping or electrical conduit is to be embedded, to act as form watchers and to reset any rebars, conduit, or piping displaced.21 As concrete is cast, the slump of the concrete must be observed and regulated within prescribed limits, or the specified strengths based on the expected slump may be reduced.An inspector of placing who is also responsible for sampling and making cylinders, should test slump, temperatures, and unit weights, during concreting and should control any field adjustmentThe inspector should also that handling, placing, and finishing procedures that agreed on in advance are properly followed, to avoid segregated concrete.should ensure that any construction joints made necessary by stoppage of concrete supply, rain, or other delays are properly located and made in accordancewith procedures specified or approved by the engineer.22 Inspection is complete only when concrete is cast, finished, protected for curing, and attains full strength.1混凝土适当放置的原则是：2在混合器和放置点之间的所有操作（包括最终固结和精整）期间必须避免分离。

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。

2021年最新混凝土搅拌站毕业论文外文翻译（完整版）

一.外文翻译CONCRETE MIXING PLANTThe apparatus of the present invention relates generally to concrete mixing plants and more specifically to such plants utilized to automatically and continuously mix separate concrete components into a wide range of predetermined quantities or batches.Conventional concrete plants and mixer trucks that can normally only be utilized for mixing single large batches of concrete. Such apparatus often are preset to mix a batch that is too large for a specific job. The remaining concrete must either be dumped or resold. If the remaining concrete is to be resold, it often must be watered down before it reaches the second job site.Conventional truck-mounted mixers are necessarily large in volume, to accommodate the labor cost of the individual driver. Furthermore, the concrete must be used within a fixed time span from its receipt in the truck. Delays in transit or unforeseen delay at the site of usage make it difficult to maintain a constant delivery schedule. Usually excess trucks and drivers must be used to assure a ready supply of concrete.Much greater control of concrete consistency and cost is possible by on-site mixing. However, conventional concrete mixers are designed for large scale batch mixing. The mixer described below fills the need for an on-site mixer readily adjustable to meet the instant demands of the user asto quantity and quality.A further problem is that with a premixed batch, it is difficult or impossible to make last minute adjustments in mixture proportions. This difficulty arises frequently in areas where quick climate changes are common and further, where specific building construction techniques call for different concrete stress characteristics.These problems are realized to a limited degree by the apparatus disclosed in U.S. Pat. Nos. 3,339,898 and 3,469,824 granted to Futtyetal. These patents disclosed mixing methods and mixing truck constructions where in concrete components are supplied to an elongated trough. An elongated shaft is provided within the trough having a plurality of spatially disposed mixing paddles and helical feeding screws. Rotation of the shaft simultaneously mixes the particulate ingredients and moves them toward an output end.U.S. Pat. No. 3,310,293 granted to Zimmerman discloses a concrete mixing and delivery system wherein concrete components are held within a plurality of bins supported on a truck frame. The components are held separately within the bins that provide means for dispensing predetermined amounts of the components onto an elongated conveyor belt. The conveyor delivers the separate components to an external mixing trough where water is applied to the dry components and they are mixed by an elongated auger within the mixing trough.Another patent granted to Futty, U.S. Pat. No. 3,336,011, discloses a system and means for selectively mixing concrete and incorporating additives therein which, like the Zimmerman apparatus, deposits concrete components onto a conveyor and delivers them separately to a mixing trough. Water is added to the components at the mixing trough as an auger is rotated to mix the components together. The principal feature of this invention is the provision of separate water supply systems in which either pure water or an antifreeze solution may be selectively applied to the mixture.A further patent granted to Futty, U.S. Pat. No. 3,623,708 discloses a system and means for selectively mixing concrete and incorporating dry additives therein. The apparatus includes means for delivering dry additives to the concrete batch and incorporates a hopper assembly for holding the dry additives. The hopper contains agitator means for mixing and breaking up the dry additive ingredients. A controlled feed means selectively controls the amount of dry additives passed from the hopper into an enclosed auger arrangement. The additives are conveyed by the auger arrangement into an auxiliary mixing trough where they are incorporated into a concrete batch. U.S. Pat. No. 2,976,025 granted to G. M. Pro discloses a combined mixer and conveyor for concrete components. Individual hoppers are used in the Pro apparatus for storing each concrete component. The apparatus includes means for deliveringsand and cement to a helical conveyor within a trough. The materials are received within the trough and tumbled and agitated as they are moved upwardly.Another U.S. Pat. No. 2,946,597, granted to M. W. Simonsen, discloses a fertilizer mixer and spreader with a partition container wherein fertilizer components are kept separately in longitudinally spaced bins. The bins include bottom openings through which the individual components are placed onto a conveyor and delivered to a fertilizer dispensing impeller. The fertilizer dropped onto the impeller is spread across the ground behind the supporting vehicle.U.S. Pat. No. 796,591 granted to W. B. Martin describes a concrete mixer in which individual concrete components are contained within separate hoppers. The apparatus includes means for removing measured amounts of gravel, stone, cement and sand in predetermined quantities and dropping them gravitationally downwardly into a mixing auger.It may be noted that each of the above-cited patents r elating to an apparatus f or mixing separate c oncrete components utilizes an auger or paddled wheel arrangement as means for mixing the components together. The apparatus of the present invention differs from this art in that the mixing of the components is accomplished by impact and shearing action. Mixing by impact is accomplished as the components are propelled against a stationary abutment surface, while mixing by shearing layers orstrata of the components is affected as the components are delivered from storage bins or fall from the abutment surface onto to second conveyor belt or other receiving conveyor.SUMMARY OF THE INVENTIONA concrete mixing plant is described comprising conveyor means for carrying concrete component mater als along a first direction of travel toa discharge point where they are propelled against an upright abutment surface. Supply means is also provided for placing controlled quantitiesof concrete component materials onto an upwardly facing surface of the conveyor means.It is a first object of my invention to provide a concrete mixing plant that is capable of producing a continuous supply of consistent wet concrete.Another object is to provide such a plant that may be controlled while in operation, to change mixture proportions and the consistency of the concrete produced.It is an additional object of my invention to provide such a concrete mixing plant that is relatively simple in3construction and therefore easy to operate. It can be transported to the job site or used as a central mixing plant.A yet further object is to provide such a mixing plant that includesseparate storage bins for each individual concrete component with a metering and discharge mechanism attached to each bin to facilitate control of the quantity of each individual component supplied to the mixture.These and further objects and advantages will become apparent upon reading the following disclosure which, taken with the accompanying drawings, discloses two preferred forms of the present invention.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a pictorial view of a first embodiment of the mixing plant;FIG. 2 is an enlarged elevational section view taken substantially along line 2—2 in FIG. 1;FIG. 3 is an enlarged elevational section view taken substantially along line 3—3 in FIG. 1;FIG. 4 is an enlarged elevational section view taken substantially along line 4—4 in FIG. 1;FIG. 5 is a fragmentary operational view taken substantially along line 5—5 in FIG. 1;FIG. 6 is a section view illustrating a weighing mechanism utilizedin conjunction with the present invention;FIG. 7 is a plan view of a slurry mixing mechanism incorporated inthe present invention;FIG. 8 is a cross sectional view taken substantially along line 8—8in FIG. 7;FIG. 9 is a plan view of a mixing plant mounted to a truck frame;FIG. 10 is an elevational view of the plant and truck as shown in FIG. 9;FIG. 11 is a sectioned view taken along line 11—11 in FIG. 9; andFIG. 12 is a fragmentary sectioned view taken along lines 12—12 in FIG. 9.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTSA first embodiment of the concrete mixing plant invention is illustrated in FIGS. 1 through 8 of the attached drawings and is generally designated therein by the reference numeral 10. A mixing plant 10 as shown, is supported by a framework 11. A plurality of component bins 12 and a dry cement bin 12a are located on the framework for receiving and storing individual concrete components such as sand, various size aggregate and, of course, dry cement.The component bins are elements of a supply means whereby the individual concrete components are placed in controlled layered quantities on an upwardly facing surface 13 of first and second conveyor means 14 and 26 respectively. In operation, the supply means is utilized to deliver dry concrete components to the first conveyor means 14 which in turn initially moves the components along a first direction of travel to adischarge end 15. The dry components fall from discharge end 15 ontothe second conveyor means 26. A wet cement slurry is added to the components as they move along on the second conveyor means 26 to a second discharge end 33. The components leave the discharge end 33 as a concrete mixture.混凝土搅拌站本发明的装置本发明一般涉及混凝土搅拌站，更具体地说，涉及这样的植物，利用自动连续到范围广泛的预定量或分批混合单独的混凝土构件。

毕业论文外文翻译-建筑施工混凝土开裂预防加工

毕业论文外文翻译-建筑施工混凝土开裂预防加工Prevention and Treatment of Concrete Cracks in Building ConstructionAbstract：Concrete is widely used in building construction because of its advantages such as durability, strength and low maintenance cost. However, concrete cracks can not only affect the aesthetic appearance of buildings, but also have negative impact on structural integrity and durability. This paper focuses on the prevention and treatment of concrete cracks in building construction. Firstly, the causes of concrete cracking are analyzed, including shrinkage, thermal stress, structural design, material quality and construction quality. Then, preventive measures in design and construction are proposed, such as proper reinforcement arrangement, control of concrete mix proportions, proper curing and protection after pouring, etc. Treatment measures for existing concrete cracks include surface treatment, filling and injection, and reinforcement. Finally, some new techniques are briefly introduced, such as fiber-reinforced concrete, self-healing concrete and material testing technology. This paper provides a comprehensive understanding of the prevention and treatment of concrete cracks in building construction, and proposes practical solutions to improve the quality of concrete structures.Key words: concrete cracks; building construction; prevention; treatmentIntroduction：Concrete is a popular building material due to its properties such as durability, strength and low maintenance cost. However, concrete cracking is a common problem in building construction, which can not only affect the aesthetic appearance of buildings, but also have negative impact on structural integrity and durability. Therefore, preventing and treating concrete cracks are crucial to ensure the long-term performance of buildings. This paper analyzes the causes of concrete cracking in building construction, and proposes preventive and treatment measures based on practical experience and research.1. Causes of Concrete Cracking：1.1 ShrinkageShrinkage is the most common cause of concrete cracking, which is due to the decrease in volume of concrete as it dries and hardens. Shrinkage can be classified into autogenous shrinkage, plastic shrinkage and drying shrinkage.Autogenous shrinkage is caused by the chemical reaction between water and cement, and it can lead to micro-cracks. Plastic shrinkage is caused by the evaporation of water from the surface of fresh concrete, which can cause cracks in the surface layer. Drying shrinkage is caused by the loss of moisture from the hardened concrete, which can lead to cracks in the bulk of the structure.1.2 Thermal StressThermal stress is another cause of concrete cracking, which is due to the temperature difference between the interior and exterior of concrete. When the temperature change is rapid or large, thermal stress can exceed the tensile strength of concrete and cause cracking.1.3 Structural DesignPoor structural design can also cause concrete cracking. For example, inadequate reinforcement or improper placement of reinforcement can lead to excessive stress concentration and cracking. In addition, insufficient structural support or improper joint design can also cause concrete cracking.1.4 Material QualityThe quality of concrete materials such as cement, aggregates and water can also affect concrete cracking. Poor quality materials can result in uneven shrinkage, low strength, and high water permeability, which can cause cracking.1.5 Construction QualityConstruction quality is an important factor in the prevention of concrete cracking. Improper placement, compaction and curing of concrete can lead to poor quality, which can cause cracking. In addition, inadequate protection measures such as insufficient cover or damage to the surface layer can also cause cracking.2. Prevention of Concrete Cracking：2.1 Reinforcement ArrangementProper reinforcement arrangement is essential to prevent concrete cracking. The size, spacing and distribution of reinforcement should be designed according to the structural requirements and the characteristics of concrete. In addition, the use of fiber reinforcement can improve the crack resistance of concrete.2.2 Control of Concrete Mix ProportionsThe control of concrete mix proportions is critical to the prevention of concrete cracking. The ratio of water to cement, the type and quality of aggregates, and the use of admixtures should be carefully considered to ensure proper workability and strength of concrete.2.3 Proper Curing and ProtectionProper curing and protection measures can effectively prevent concrete cracking. Adequate moist curing can reduce evaporation and shrinkage, and increase strength and durability. In addition, proper protection measures such as sufficient cover and protective coatings can protect the surface layer of concrete from damage.3. Treatment of Concrete Cracks：3.1 Surface TreatmentSurface treatment is a common method to repair concrete cracks. The damaged concrete is removed, and the surface is cleaned and roughened. Then, a bonding agent is applied and a new layer of concrete is poured to fill the crack.3.2 Filling and InjectionFilling and injection is another effective method to repair concrete cracks. The crack is filled with cementitious material, such as epoxy or polymer, to restore theintegrity of the structure. Injection is also used to repair cracks in reinforced concrete structures, where the material is injected under pressure to fill the voids and cracks.3.3 ReinforcementReinforcement is used when the crack is severe and structural integrity is compromised. Steel bars or plates are installed into the crack and bonded to the surrounding concrete to restore the strength and load-carrying capacity of the structure.4. New Techniques：4.1 Fiber-Reinforced ConcreteFiber-reinforced concrete is a new type of concrete that contains short fibers, such as glass, steel or synthetic fibers, which can improve the crack resistance and toughness of concrete.4.2 Self-Healing ConcreteSelf-healing concrete is a novel material that can repair micro-cracks by itself through the chemical reaction between water and the embedded capsules.4.3 Material Testing TechnologyMaterial testing technology such as acoustic emission and electrical resistance can effectively detect and monitor the formation and propagation of cracks in concrete structures, and provide early warning for potential failures.Conclusion：Concrete cracking is a common problem in building construction, which can affect the aesthetic appearance, structural integrity and durability of buildings. This paper analyzes the causes of concrete cracking, and proposes practical preventive and treatment measures to improve the quality of concrete structures. In addition, some new techniques such as fiber-reinforced concrete, self-healing concrete andmaterial testing technology are briefly introduced. With proper design, construction and maintenance, the occurrence and impact of concrete cracking can be effectively reduced, and the long-term performance of concrete structures can be ensured.。

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