外文翻译--土木工程中新型混凝土.doc

本科毕业设计（论文）外文翻译译文学生姓名： 黄磊 院 （系）： 机械工程学院 专业班级： 土木0801 指导教师： 田晓艳 完成日期： 20 年 月 日 西安石油大学本科毕业设计（论文）土木工程中新型混凝土A new generation of concrete in civil engineering作者： A.Kmita* Institute of Building Engineering, Technical University of Wroctaw, Pl.Grunwaldzki 11, 50-371Wroctaw, Poland起止页码：80-86出版日期（期刊号）：Journal of Materials Processing Technology 106 (2000)外文翻译译文： 摘要本文介绍在新一代的水泥基混凝土技术发展研究中当前先进的趋势，文章提出了目前已经很难从所谓普通混凝土获得这中混凝土的分类和它的特有物理特性。新的混凝土给出了混合物成分和比例的例子，文中强调的主要是由于它的高强度以及对环境的影响无法得到的抵抗力，这种特点增加在最困难的条件下以及在与钢结构竞争的许多情况下混凝土结构应用的可行性。文中给出了在不同的技术分支中新型混凝土应用的例子，关注于编纂至少一级考试的欧洲规范规则和高强度混凝土(HSC)制成的材料和结构设计的必要性。关键词： 高强度混凝土 ；结构1.介绍第二次世界大战后迅速发展的建筑及土木工程的特点是混凝土基础材料在所有的经济部门中得到了广泛的应用。在建筑、 结构及土木工程 （例如塔、 海洋结构等）中新的结构类型、 新技术为这种材料提出了更加困难的要求。为了达到这些要求，主要是在欧洲和美国的研究已经启动。这项研究的结果是新一代的混凝土克服了普通混凝土的弱点。在规范和标准分类上混凝土的基本属性是其抗压强度，但当代土木工程从混凝土中需要的不仅仅是强度。2.目前混凝土的分类根据在混凝土配料和生产技术的最新成果的以下的水泥基混凝土分类由： (一) 常规混凝土-CC，强度达60 MPa ；(二) 高强度混凝土-HSC， 强度60-90 MPa ；(三) 很高强度混凝土-VHSC、强度达90 -130 MPa；(四) 活性粉末混凝土-RPC、强度达200-800 MPa ；(五) 高性能轻质混凝土- HPLC大于55 MPa。混凝土的基本特征即其抗压强度通常用这种分类，除了介绍这种高性能混凝土(HPC)的概念，这种概念引入的必要性源于还确保某些土木工程分支中除了其抗压强度外混凝土的其他高级参数的需要。最常见的参数是： 吸收性能、 渗碳率和冻结可磨性与抵抗，对于侵略性的环境他们通常产生高的抵抗，高性能混凝土混凝土通常也是 HSC 或甚至 是VHSC。这些高性能混凝土的功能是桥梁、 工业和城市建筑中的应用和任意程度的预应力混凝土结构的首选。很明显用的混凝土生产工艺过程有影响的组成 1，2，作者的研究与生产预应力混凝土输水管 1，2 连接。3.高强度混凝土的特征属性如果考虑强度参数，那么高强度和常规混凝土的抗压强度时间增量的差异将很好的被介绍。高强度混凝土功能允许加速的建设，例如48 h后混凝土浇筑预应力结构。小于常规混凝土对于抗压强度加载速度的影响、 略高的泊松比和重大的极限应变被观察到，有趣的是在受控制的纵向变形的实验中这种混凝土在获得应力的最大值后展现出应力应变关系反弹现象。古典强度试验中样品会爆炸，所以他们行为不同于传统的混凝土，这也是特色的破坏行为，这是因为在高强度混凝土中更大破坏能源被观察到。从设计的角度来看为适当的混凝土等级提供一个合适的特征强度水平是重要的，显示针对该问题的荷兰规定 3，他们接近德国规定 4。在混凝土技术上进程的特定的区别主要是用作纤维混凝土复合材料的RPC 5，今天，他们分两个等级生产：RPC- 200 和 RPC- 800，这两个等级的基本参数在表1中。RPC- 800 存在仅作为纤维混凝土。（表1 RPC的特性）RPC-200RPC-800预置加压None50Mpa热处理20-90250-400抗压强度170-230MPa490-810Mpa抗弯强度30-60Mpa45-141Mpa断裂能20000-40000J/1200-20000J/杨氏模量50-60Gpa65-75Gpa它是真正的新生代水泥混凝土，此外，此混凝土展现出异常高的气体渗透、 吸水能力、 渗碳以及抗冻和可磨性参数，这种类型的材料预计将用于修建柱子、 预应力的构件、 工业地坪、 薄板坯、 桥面或叠加、 桥梁轴承、 关节和其他组件、 地震联合和抑尘剂的位置、 护栏、 磨损、 爆炸或耐冲击产品、 安全和防火门、 安全金库，耐磨容器，运输容器、 储罐、 预应力锚固、 模具等。在轻质混凝土中，应强调按体积重量和强度之间的关系，在这一领域取得的成就根据8。4、 高强度混凝土与高性能混凝土中的应用高强度混凝土在预应力混凝土结构中特别有用，它可以应用于土木工程不同的分支，虽然今天在某些组的专家和专门的运用习惯的结果有一些阻力。例如，根据 PCI 9 的研究高性能混凝土实际应用的过程生产预制混凝土构件上是非常缓慢的，看来在土木工程中预制是一个比较保守的分支，工程师对较高级别控制技术、 额外的培训等介绍不感兴趣。另一原因可能是，根据 PCI 研究批量生产组织和不断提供的高强度混凝土不高于订单，从这次研究中得出高强度混凝土在下列类型的结构中应用最频繁（与公用地方的结构）： (一) 预制柱-45%；(二) 桥梁 (预应力）-40%；（三） 泊车位及车库-20%；(四) 桩 10%；建筑上的细部构造-10%。这种趋势在未来可能会更改。在艺术的基础上看，在工程实践中高强度和高性能混凝土的应用的几个例子被提出，这种混凝土的应用重要的例子是在荷兰的建筑，在布雷达办公大楼整体结构由混凝土等级 C95构成，在此结构中，地板的跨度没有额外的支持，常规高的楼在 12.60 m。这将允许一个简单的方法布局空间和墙壁的门面元素是43.0米长的无伸缩缝，墙壁及地面的施工周期是1天。由于高性能混凝土的应用，以减少了68%部分是可能的，这是首次在荷兰的高性能混凝土结构。在波兰市政工程 （水线和污水系统）中的高性能混凝土应用的一个有趣的例子是两个定向预应力管道，根据作者的文章高性能混凝土的使用使它们的应用成为可能。例如在大的动荷载作用下运输工程和工业建筑中的应用，高性能混凝土应用的其他示例是在北海附近挪威埃科菲斯克海洋平台的生态保护屏障，为了确保这些预应力的障碍，使用了 V75/80 混凝土的特殊要求。巨魔是最大的混凝土平台之一，平台有472米的总高度。混凝土重力坝结构包含245000立方米的高强混凝土，这张照片显示了平台并且和伦敦塔桥结构比较。高性能混凝土在预应力混凝土结构中的一个非常有趣的例子是在没有振动和噪音的情况下应用桩的特殊混凝土线程拧到土里，这种桩的最佳直径是 0.50- 0.60 m。因为高混凝土参数很可能在污染地面中使用这些点，桩柱第一次被用于乌得勒支 1992年7 的铁路高架桥施工中。这种类型的混凝土将无疑在直布罗陀潜在设计的桥梁建设中使用，计划将有两个塔架的变种： 第一个是1075米高度 （625 米船的甲板上） 第二个是高1350 米 （900 米的甲板上）。在未来办公室大楼中，变截面的预制柱将被构建，柱的顶部和底部的部分是由混凝土C60构成和中间部分由C120构成。在诺曼底桥的建造中。由于运用了高性能混凝土，中铁塔的截面墙从0.60米减到0.40米，减少了30%，在欧洲最大的桥梁结构中，这给了重大的经济影响。1988 年在路易斯安那州高性能混凝土的应用对经济的影响也是通过了确认，因为桥梁施工用高强混凝土使成本减少了25%，这主要的梁的数目从9根减少到4根，板的厚度仅仅增加了2.5 厘米和大幅度降低运输和安装。高性能混凝土还用在波兰克拉科夫附近的大桥的建设，在维斯杜拉河上的设计理念之一是，高性能混凝土的使用也是桥的预测。10 提供了一个有趣的RPC使用的命题，提供了从无被动筋的高级纤维混凝土预应力混凝土结构的应用，在缺乏横向加固，尽管开裂没有发生在支持区和在没有钢筋混凝土受压区的破坏下不破二取得限制容量是很重要的。对可能的情况一般高强度混凝土将会使用在烟囱，电视塔，等高层建筑和高层公共建筑，对于最后一组的结构一个有趣的分析了在 11。有趣的是注意由高强度预应力的混凝土加固的老观念在12中的加固与演出的实验证明了这种解决办法的优势。表2给出了高层混凝土结构与 2000年的高层建筑建设命题的集合高强度混凝土可能使用 13。5.结论新一代混凝土的领域的技术研究中的当前的尝试尚未结束，新的改进或甚至是全新的概念除外。同时，基于水泥混凝土的新类型的的正式命令需要被注意到，高强度、 高性能混凝土（挪威，1999年） 的示例被提到。至少对于欧洲规模（欧洲规范、标准的国家）的标准化的迫切需要的问题在目前新一代混凝土设计中体现了。这个问题还会出现当考虑有关实验室的方法论和原位测试材料和施工。表2世界上最高的混凝土结构建筑地点高度(米)完成时间双子塔吉隆坡4501996中央广场香港3741992伟基河畔南311号芝加哥2921989水塔芝加哥2621976商品交易会大厦法兰克福2531990纽约城市之尖中心纽约2481988圣马可中心墨尔本2431987千年塔与摩天大楼伦敦千年中心伦敦376上海金融中心上海460纽约双子塔纽约546孟买千年塔孟买560东京千年塔东京840直布罗陀跨越塔西班牙摩洛哥1350A new generation of concrete in civil engineeringA.Kmita* Institute of Building Engineering, Technical University of Wroctaw, Pl.Grunwaldzki 11,50-371Wroctaw, PolandJournal of Materials Processing Technology 106 (2000) 80-86AbstractThis paper presents current tendencies in the state-of-the-art in research on technology development in a new generation of cement-based concrete. The classification of such concrete and its characteristic physical properties that have been difficult to achieve up to the present time for so-called ordinary concrete are presented. The examples of mixture ingredients and proportions are given for the new concrete. It is particularly of high strength and hither to unobtainable resistance to environmental impact are highlighted . Such features increase the application possibility of concrete structures in the most difficult conditions and in many cases they are competitive with steel structures . Examples of the applications of the new concrete in different branches of technology are given . Attention is paid to the necessity of codifying at least at the level of Eurocode rules of the examination and design of the material and structures made from high strength Concrete (HSC). Keywords: High strength concrete; Structures1.IntroductionThe rapid development of building and civil engineering after the second world war is characterised by wide application of concrete as the basic material in all bran- ches of the economy . New types of structures and new technologies in buildings , structural and civil engineering (i. g. towers , marine structures , etc.) created more difficult requirements for this material.To reach these requirements, research mainly in Europe and USA has been started. The results of this research is a new generation of concrete that overcomes the weaknesses of ordinary concrete . The basic property that classifies concrete in codes and standards is its compressive strength, but conte- mporary civil engineering requires from concrete not only strength.2.The present classification of concreteAccording to the latest achievements in concrete ingredients and the technology of production the following cement-based concrete classification is made : (i) conventio-nal concrete -CC, up to grade 60 MPa; (ii)high strength concrete - HSC, grades 60 -90 Mpa ; (iii) very high strength concrete VHSC , grades 90 -130 Mpa ; (iv) reactive powder concrete RPC , grades 200-800 Mpa; (v) high performance lightweight con-crete-HPLC greater than 55 MPa.This classification is used commonly from the position of the basic feature of concrete, which is its compressive strength. Apart from this a notion of high performance concrete (HPC) was introduced. The necessity of the introduction of this notion arose from the needs to ensure in certain civil engineering branches also other high parameters of concrete apart from its compressive strength. The most common parameters are: absorbability, carbonisation and “freeze resistance and grindability”. They usually lead to high resistance to an aggressive environment. HPC concrete is usually also HSC or even VHSC.These features of HPC are preferred in application to bridges, industrial and municipal buildings and also in prestressed concrete structures of arbitrary degree of prestress.It is obvious that the technological process of the concrete production used has an influence on the composition 1,2. The authors research is connected with production of prestressed concrete pipes 1,2.3.Characteristic properties of HSCIf the strength parameters are concerned, the differences in the compressive strength time increment of high strength and conventional concrete are well presented.HSC features permit accelerated construction, for example to prestressed structure 48 h after concrete placement. Smaller than in conventional concrete, the influence of load velocity on the strength, a slightly higher Poissons ratio and a significant ultimate strain are observed. It is interesting that in experiments with controlled longitudinal deformation this concrete exhibits snap-back behaviour in relationship after maximum value of is achieved. In the classical strength test the specimens explode and so they behave differently from the failure behaviour of conventional concrete, which is also characteristic. This is because in HSC greater fracture energy is observed.From the design point of view it is important to assume an appropriate characteristic strength level for appropriate concrete grades. Dutch provisions 3 for that issue are presented. They are close to the German provisions 4.A particular distinction of progress in concrete technology is RPC 5 used mainly as fibre-concrete composites. Today they are produced in two grades: RPC-200 and RPC-800, the basic parameters for both grades being presented in Table 1. RPC-800 exists only as a fibre-concrete.Table 1Characteristic of RPC 5RPC-200RPC-800Presetting pressurisationNone50MpaHeat-treating20-90250-400Compressive strength170-230MPa490-810MpaFlexural strength30-60Mpa45-141MpaFracture energy20000-40000J/1200-20000J/Youngsmodulus50-60Gpa65-75GpaIt is a really new generation of cement concrete. Moreover, this concrete exhibits exceptionally high gas permeability, water absorbability, carbonisation freeze resistance and grindability parameters. This type of material is predicted to be used in building columns, prestressed members, industrial floors,thin slabs, bridge decks or overlays, bridge bearings, joints, and other components, seismic joint and restrainer locations, guardrails, abrasion, blast or impact resistant products, security and fire doors, security vaults, waste containment, transportation vessels, storage tanks, prestressing anchorage, moulds, etc. The relationship between strength and weight by volume should be emphasised in light-weight concrete. The achievements in that field are well presented according to 8.4.Application of HSC and HPCConcrete of high strength is particularly useful in prestressed concrete structures. It can be applied in different branches of civil engineering, although today there is some resistance that is the result of habits in some groups of specialists and specialised plants. For example, according to PCI 9 research the process of practical application of HPC is very slow in plants producing precast concrete elements. It appears the precasting in civil engineering is a rather conservative branch and engineers are not interested in the introduction of higher level control technology, extra training, etc. An additional reason may be, according to PCI inquiry, mass production organisation and constant providing of orders for no more than HSC. It is also concluded from this inquiry that HSC application is the most frequent in the following types of structures (with common areas of the structures): (i) precast columns -45%; (ii) bridge girders (prestressed) -40%; (iii) parking and garages -20%; (iv) piles-10%; architectural details -10%. This tendency may change in the future.On the base of literature reviewed, a few examples of high strength and HPC application in engineering practice are presented. Adverted examples of this concrete application are buildings in Holland. In the office building in Breda the whole structure is made from concrete grade C95, the span length of floors in this structure, without extra supports, with a conventional height of floor, being 12.60 m. This permits the arranging of space in an easy way and the faade elements of the walls are 43.0 m long without expansion joints. The construction cycle of the walls and the floors was 1 day.Due to the application of HPC, a 68% section reduction was possible. This is the first structure in Holland made from HPC.An interesting example of HPC application in municipal engineering (water line, and sewerage )in Poland are two-directionally prestressed pipes. The usage of HPC according to the authors composition made possible their application, for example in transport engineering and industrial buildings under a large dynamic loading. An other example of HPC application is the ecological protection barrier at the offshore platform Ekofisk at North Sea near Norway. To make these prestressed barriers, V75/80 concrete of special requirements was used.One of the biggest concrete platform is the Troll. The platform has a total height of 472 m. The concrete gravity structure contains 245000of HSC. The photograph (Fig. 1) shows the platform and compare the structure to Londons Tower Bridge.A very interesting example of HPC application in prestressed concrete structures are piles with a special concrete thread screwed into the soil without vibration and noise. The optimum diameter of such piles is 0.50-0.60 m. Because of high concrete parameters it is possible to use these poles Fig. 1 The Troll platformin polluted ground. The piles were used for the first time in the construction of a railway viaduct in Utrechtin 1992 7.This type of concrete will be used with no doubt in the potential construction of the designed bridge over Gibraltar. Two variants of pylons are planned: the first are of 1075 height (625 m over the deck) and the second are of 1350 m high (900 m over the deck).In Hertogenbosh in the building“Office of the Future”, a precast column of variable section (Fig.2) was constructed. The top and bottom parts of the column were made from concrete C60 and middle part from C120.In the construction of the Normandie Bridge, due to the application of HPC, a 30% reduction of box section walls in the pylons from 0.60 to 0.40 m was achieved. This gave significant economical effects in one of the biggest bridge structures in Europe.The economical effects of HSC application in Louisiana in 1988 were also by confirmed. Because HSC was used the costs of the bridge construction were reduced 25%. This was achieved by reduction in the number of Major girders from 9 to 4 with a slight increase of slab thickness by 2.5cm and significant reduction of trFig.2 Demonstation column of HSC in Office of the Future7ansport and mounting.HPC concrete was also used in Poland for the construction of the bridge near Cracow (Chabowka). In one of design conceptions of the bridge near Piock across the Vistula river, the use of HPC is also forecasted.An interesting proposition of RPC usage is presented in 10. The application of prestressed concrete structures from high-class fibre-concrete without passive reinforcement is presented. .It is important that in spite of the lack of transverse reinforcement, the cracking did not take place in the support zone and the limit capacity was achieved by breaking of the prestressing tendons without the destruction of the concrete compressive zone.On might state that in general HSC will be used in tall buildings as chimneys, TV towers, and in tall public buildings. For the last group of structures an interesting analysis was made in 11.It is interesting to note that the old idea of reinforcement made from high strength prestressed concrete is coming back 12. The experiments performed with reinforcement presented in Fig. 3 prove advantages of such solutions.Fig. 3 Cross-section of the prestressed bar12Table 2The tallest concrete structures in the worldBuildingLocationHeight(m)Year of completionTwin TowersKuala Lumpur4501996Central PlazaHongkong3741992311South Wacher DriveChicago2921989Water Tower PlaceChicago2621976MesseturnFrankfurt2531990CityspireNew York2481988Rialto CentreMelboume2431987Proposed millennium tower and skyscrapersLondon Millennium CentreLondon376Shanghai Financial CentreShanghai460New York Sock Exchange TowerNew York546Bombay Millennium TowerBombay560Tokyo Millennium TowerTokyo840Gibraltar Crossing-PylonSpain-Morocco1350Table 2 gives a collection of tall concrete structures and propositions for the construction of millennium tall buildings for the year 2000, where HSC may be used 13.5.ConclusionsThe presen tstate in technological research in the area of new generation concrete is not yet finished. New improvements or even completely new concepts are expected. Simultaneously, the need of formal order in the field of new types of cement-based concrete is noticed. The example on Utilisation of High Strength/High Performance Concrete (Norway, 1999).In the urgent need for standardisation of at least European scale (Eurocode, country standards) the problem of new generation concrete design is present. Th