03 Chapter 3 Structure Materials.pptx

第1页：第三章结构材料

Chapter 3 Structure MaterialsSection A Civil Engineering Materials

第2页：土木工程材料概述

As an engineer, one must know about the materials used in theconstruction site.

作为一名工程人员必须知道施工现场所用的建筑材料。

It is necessary for an engineer to be conversant with the propertiesof such materials.

对于工程人员熟悉这些材料的特性是必须的。

Civil engineering materials can be natural and manmade. Theycontaincement, metals, timber, concrete,bituminousetc.

土木工程材料有天然的和人造的。

它们包含水泥，金属，木材，混凝土和沥青等。

第3页：绿色土木工程材料

Now green civil engineering materials and eveneco-materials(n.生态材料)for civil engineering are recommended based on theconsideration of sustainable development.

现在，基于可持续发展，绿色土木工程材料甚至生态土木工程材料被推荐。

This has the benefits of reducing energy, saving resources andprotecting the environment, having minimum harm to human health.

这样带来的好处有降低能耗、节约资源、保护环境和最低限度的危害人体健康。

第4页：水泥的制备

Cement is obtained by burning at a very high temperature amixture ofcalcareousandargillaceousmaterials.

水泥是石灰质和粘土质材料的混合物在一个很高的温度下被焙烧制的。

Calcinedproduct is known asclinker.

焙烧的产品被称为水泥熟料。

A small quantity of gypsum is added to the clinker and is pulverizedinto very fine powder known as cement.

少量的石膏被加入到水泥熟料中然后被粉碎成非常细的粉末称为水泥。

第5页：水泥品种与外加剂

By changing the chemical composition and by using different rawmaterials and additives, many types of cements can be manufacturedto cater to the need of the construction industry for specific purposes.

通过改变化学组成以及不同原材料、外加剂的使用，来制备不同类型的水泥来迎合有特殊目的的工程建设需求。

Rapid hardening cement(快硬性水泥)is used where high strengthis required instantly in initial stages.

快硬性水泥被用在初始阶段有高强度需求的工程中。

第6页：火山灰水泥与引气水泥

Portlandpozzolanacement(火山灰质硅酸盐水泥)produces lessheat of hydration and offers greater resistance to the attack ofaggressive water.

火山灰质硅酸盐水泥的水化热很低同时可以很好地抵抗侵蚀性的水的攻击。

Air-entraining cement(引气水泥)is produced by mixing a smallamount of an air-entraining agent with ordinary Portland cement.

引气的水泥通过加入少量的引气剂和普通硅酸盐水泥混合来制备。

By adding this, the properties of concrete can be changed and italso increases the frost resistance of hardened concrete.

通过加入引气剂，混凝土的特性被改变，它能够提高硬化混凝土的抗冻性。

第7页：混凝土的组成与强度

Cement is mixed at or near the construction site with sand,aggregate (small stones, crushed rock, or gravel), and water to makeconcrete.

在施工现场，水泥和砂子、骨料（小石头，碎石或砾石）和水混合制成混凝土。

Concrete has a high and its strength depends on the proportion inwhich cement, and, stones and water are mixed.

混凝土有很高的抗压强度，并且它的强度取决于水泥、石子和水的混合比例。

It hardens with age and the process of hardening continues for along time after the concrete has attained sufficient strength.

混凝土随着龄期而逐渐硬化，当混凝土已经达到足够的强度后，水化的过程还会持续一段很长的时间。

第8页：钢筋混凝土与预应力

Normal concrete has a comparatively low tensile strength and forstructural applications it is normal practice either to incorporate steelbars to resist any tensile forces (steel reinforced concrete) or to applycompressive forces to the concrete to counteract these tensile forces(pre-stressed concrete or post-stressed concrete).

普通混凝土有相对较低的抗拉强度，对于结构应用来说，通常的做法是加入钢筋来抵抗拉力的作用（钢筋混凝土）或者是给混凝土施加压力的作用来抵消这些拉力（先张法预应力混凝土或后张法预应力混凝土）。

第9页：预制混凝土与纤维增强

It is used also for a wide range of precast concrete products whichinclude concrete blocks, cladding panels, and pipes.

混凝土也被用在大范围的预制混凝土生产当中，包括混凝土砌块、外挂板和管道。

The impact strength, as well as the, of normal concrete is low andthis can be improved by the introduction of randomly orientated fibersinto the concrete.

普通混凝土的抗冲击强度和抗拉强度是很低的，这可以通过在混凝土中随机引入乱向分布的纤维来提高。

第10页：木材资源

Timber is one of the oldest known civil engineering materials. Inaddition to its usefulness as a structural material, timber has alsofulfilled a role in temporary structures.

木材是最古老的土木工程材料。

Although timber is a kind of sustainable resource, the consumptionspeed of forests must be slowed down because of the relativeslowness of tree growth.

尽管木材是一种可再生资源，但是因为树木的生长相对较慢，因此森林的消耗速度必须减慢。

第11页：木材的性能要求

The requirements for this purpose include ease of working andfinishing, good grain pattern and appearance when clear-finished,dimensional stability in conditions of variability of temperature andhumidity, both internal and external, and resistance toinfestationandfungalattack etc.

这个目的的要求包括工作和完成的难易、好的纹理和外观和在温度、湿度、内部和外部变化条件下的尺寸稳定性、抗虫害和真菌的侵蚀等。

第12页：木材在模板工程中的应用

Nowadays timber is also playing an important role infalseworkcarpentry, such as shuttering for in-situ or precast concrete work,supporting formwork for brick or stone arch or shell forms, or jigs forglued-laminatedtimber beam or shell forms.

如今，木材在脚手架木工作业中起的作用越来越重要了，如原位立模板，预制混凝土工作，为砖、石拱桥或壳的支模，或是胶合叠层木梁或壳形的夹具等。

第13页：金属材料的应用

The applications of metals in civil engineering are wide and varied,ranging from their use as main structural materials to their use forfastenings and bearing materials.

在土木工程中，金属材料的应用是越来越广泛，并且种类越来越多，范围从它们用做主要结构材料到连接件和轴承材料。

The properties of metals which make them unique amongconstructional materials are high tensile strength,the ability to beformed into plate, sections and wire, and the weld ability.

金属具有独特的结构材料性能，如较高的抗拉强度、能被制成钢板、段、电线以及焊接性能。

第14页：金属的导电导热与腐蚀

Other properties of metals are electrical conductivity, high thermalconductivity andmetallic luster(金属光泽),which are of importancein some circumstances.

金属的其它特性是导电性、高的导热性和金属光泽，在某些情况下这些特性都是很重要的。

Perhaps the greatest disadvantage of the common metals, andsteels in particular, is the need to protect them from corrosion bymoist conditions and atmosphere.

普通金属特别是钢筋最大的缺点可能是需要保护起来免受来自潮湿条件和大气层的腐蚀。

第15页：金属的拉伸试验

The importance of metals as constructional materials is almostinvariably related to theirload bearing capacity(承载能力)in eithertension or compression and their ability to withstand limiteddeformation without fracture.

对结构材料来说，金属的重要性大多数与它们在抗拉或抗压中的承载能力和抵抗有限的变形而不致断裂的能力有关。

It is usual to assess these properties by tensile tests in which themodulus of elasticity(弹性模量), theyield stress(屈服应力), thetensile strength and the percentageelongationcan be determined.

通常采用拉伸试验来评估这些特性，在这个拉伸试验过程中，弹性模量、屈服应力、抗拉强度和伸长率都能通过测试确定。

第16页：沥青材料

Bituminous materials are for the most part in mixtures withmineral or other aggregate.

沥青材料大部分是与矿物或其它骨料混合使用。

Thin coating of bitumen paints oremulsionapplied to absorptivematerials have the effect of sealingcapillariesso that both water andwater vapour are prevented from moving through the materials.

将薄的沥青涂料或乳液应用到吸收材料上，对封闭毛细管有影响，这样水和水蒸气就被阻止通过材料。

第17页：练习一 填空题

EXERCISEⅠ. Fill in the blanks with the information given in the text.1.Calcinedproduct is known _______clinker. A small ________ofgypsum is added ________ the clinker and is pulverized________very fine powder known as ________.2. It hardens with ________ and the process of ________continues ________a long time after the concrete has attainedsufficient strength. By virtue ________ the ease with freshconcrete in its ___________may bemoulded________any shape itmay be used for ________ purposes.3. Other properties of metals are________ conductivity, high________conductivity and ________ luster, which are ________importance in some circumstances.ofmetallicthermalelectricaldecorativeintoplastic stateofforhardeningagecementintoquantitytoas

第18页：Section B 钢筋混凝土

Chapter 3 Structure MaterialsSection B Reinforced Concrete

第19页：钢筋混凝土的主导地位

In many including the Unite State and Canada, reinforced concreteis a dominant structural material in engineered construction.

在包括美国和加拿大的许多国家，钢筋混凝土在工程结构中是一种主导结构材料。

The universal nature of reinforced concrete construction stemsfrom the wide availability of reinforcing bars and the constituents ofconcrete, gravel, sand, and cement, the relatively simple skillsrequired in concrete construction, and the economy of reinforcedconcrete compared to other forms of construction.

钢筋混凝土结构的特性就是源于钢筋、混凝土、砾石、砂子和水泥这些材料可以很容易获得，以及混凝土工程施工过程中相对简单的技术和与其它结构形式相比的经济性。

第20页：混凝土的抗拉缺陷

As we know, concrete has comparatively low tensile and bendingstrengthcompared to its high compressive strength, and concrete iseasy tocrackeven under a very low stress.

我们都知道，与较高的抗压强度相比，混凝土抗拉和抗弯强度相对较低，甚至在较低的应力作用下，混凝土也很容易开裂。

For structural applications it is normal practice to incorporate steelbars to resist any tensile forces.

在结构应用方面，通常的做法是利用钢筋来抵抗拉力。

第21页：钢筋的抗拉优势

Steel reinforcement is used in the concrete, can overcome thedeficiencies in the tensile and bending strengths of concrete.

钢筋用在混凝土当中，能够克服在混凝土拉伸和弯曲过程中的一些不足。

Compared with concrete, the enormous advantage of steel is itstensile strength; that is, it does not lose its strength when it is under acalculated degree oftension, a force which, as we have seen, tends topull apart many materials.

与混凝土相比，钢筋的最大优点是抗拉强度；也就是说，它在一定的拉力作用下，钢筋的强度不损失，正如我们看到的，这个拉力能够使得许多材料被拉开。

第22页：钢筋与混凝土强度对比

The useful strength of ordinaryreinforcing steels(钢筋)in tensionas well as compression, i.e. the yield strength, is about 15 times thecompressive strength of common structural concrete, and well over100 times its tensile strength.

在普通的钢筋当中，抗拉强度同抗压强度一样有用，如屈服强度，大约是普通结构混凝土抗压强度的15倍，是它的抗拉强度的100倍。

Although steel occupies only a small part of the volume ofreinforced concrete (on the average about 2 per cent), it is a majorpart of the cost.

虽然钢筋只占钢筋混凝土体积的一小部分（大约是2%），它却占据成本的主要部分。

第23页：钢筋混凝土梁配筋

It follows that the two materials are best used in combination if theconcrete is made to resist the compressive stresses and thecompressive force,longitudinalsteel reinforcing bars are locatedclose to the tension face to resist the tension force, and usuallyadditional steel bars are so disposed that they resist the inclinedtension stresses that are caused by theshear force(剪力)in thebeams.

如果混凝土被用来抵抗压应力和压力，纵向钢筋被放在受拉力一侧用来抵抗拉力，其它的附加钢筋用来抵抗由剪力引起的斜向拉应力，这样两种材料组合使用最佳，如钢筋混凝土梁。

第24页：受压构件中的钢筋

However, reinforcement is also used for resisting compressiveforces primarily where it is desired to reduce the cross-sectionaldimensions of compression members, as in the lower-floor columnsofmultistory buildings(多层建筑).

然而，在一些期望减少截面尺寸的受压构件中，钢筋通常也主要被用来抵抗压力，像用在多层建筑物中的低层柱中。

Even if no such necessity exist, a minimum amount ofreinforcement is placed in all compression members to safeguardthem against the effects of small accidental bending moments thatmight crack and even fail an unreinforced member.

即使没有这种必要存在，少量钢筋被用在所有的受压构件中可以保证它们免受小的附加弯矩的影响，这个弯矩能使得构件开裂甚至可能使得无筋构件破坏。

第25页：钢筋与混凝土的黏结

They also complement each other in another way: they havealmost the samerate of contraction and expansion .

钢筋和砼还有另一个互补优势：它们的收缩率和扩张率几乎相同。

Steel rods areembeddedin concrete to makereinforced concrete(配筋混凝土，钢筋混凝土)in concrete beams or structures wheretension will develop.

钢筋嵌入砼内形成钢筋砼，可用于有拉力产生的砼梁或结构中。

The properadhesionbetween the steel and the concrete is of thegreatest importance, and bars should be of a sufficiently smalldiameter to offer an adequate area of contact with the concrete.

砼和钢筋之间也形成很大的黏结力使钢筋不能从砼中滑出,同时，钢筋的直径应该足够地小以提供钢筋与混凝土之间充足的接触面积。

第26页：钢筋布置限值

The practical limit is reached when the bars become so numerousthat they obstruct the proper placing of concrete.

当钢筋的数量很多时以至于要阻碍混凝土的合理浇注时，此时达到了钢筋直径的合适限值。

Concrete and steel form such a strongbond—the force that unitesthem—that no relative movements of the steel bars and thesurrounding concrete occur.

混凝土和钢筋之间形成一种强大的粘合力，这个力能够将它们粘结在一起使得周围混凝土和钢筋不产生相对的滑移。

第27页：黏结力的三个来源

This bond is provided by the relatively large chemical adhesionwhich develops at the steel-concreteinterface, by the naturalroughness of themillscale ofhot-rolled(热轧)reinforcing bars, and bythe closely spacedrib-shaped surface(肋形表面)deformations withwhich reinforcing bars are furnished in order to provide a high degreeofinterlockingof the two materials.

这种粘合力是由产生在钢筋混凝土表面的相对较大的化学附着力、热轧钢筋工厂的原始粗糙度以及带肋钢筋表面的间隔较小的变形所提供的，这种带肋钢筋主要是为了使两种材料有很高的联结。

第28页：镀锌与环氧涂层钢筋

In order to minimizecorrosionof reinforcement and consequentspallingof concrete under severe exposure conditions such as inbridge decks subjects to deicing chemicals,galvanizedorepoxy-coated(环氧涂层的)rebar may be specified.

为了减小钢筋的腐蚀和随之而来的混凝土剥落，一些镀锌或环氧涂层钢筋被指定使用。

第29页：钢筋连接与幕墙演变

The steel stress is thus transmitted to the concrete by bond oranchorage, and it is then transmitted to another bar by the samemeans.

这些钢筋在混凝土中被连接，钢筋应力通过粘合力或锚具传递给混凝土，然后通过同样的方式再传递给另一根钢筋。

The adoption of structural steel and reinforced concrete causedmajor changes in traditional construction practices.

结构钢和钢筋混凝土的应用导致了传统结构做法的重大变革。

In the earlier steel of concrete frame building, the curtain wallswere generally made of masonry，they had the solid look ofbearingwalls(承重墙).

在早期的钢筋混凝土的框架结构，幕墙通常是用石头做成的，它们有承重墙坚实的外观。

第30页：现代轻质幕墙

Today, however,curtain walls(幕墙)are often made of lightweightmaterials such as glass, aluminum, of plastic, in cariouscombinations.

然而在今天，幕墙通常是由轻质材料做成的，如玻璃、铝、塑料等不同材料的组合。

It was no longer necessary to use thick walls of stone or brick formultistory buildings, and it became much simpler to build fire-resistant floors.

多层建筑物的建造也不再需要用石头或砖来砌筑厚墙了，同时建造耐火的楼面板也变得很简单。

第31页：练习一 填空题

EXERCISEⅠ. Fill in the blanks with the information given in the text.1. They also complement each other in another way: they havealmost the same rate ________ contraction and expansion.2. Still another advantage is that the steel is therefore completelysurrounded by the ________ and the ________ does not rust inconcrete. Acid corrodes steel, whereas concrete has an_________________ reaction, the opposite of ________. In orderto minimize ________ of reinforcement and consequent________of concrete under severe exposure conditions such as inbridge decks subjects to ________________, galvanized orepoxy-coatedrebar may be specified.spallingdeicing chemicalsacidalkaline chemicalconcretecorrosionsteelof

第32页：练习二 英译汉

EXERCISEⅡ. Translate the following passages from English into Chinese.As the cement hydrates，large amount ofettringiteareformed．When the concrete sets and develops strength, it willbond to the reinforcement and at the same time start expanding ifsufficient quantities of curing water are present. Since theconcrete is bonded to steel, its expansion under the restraininginfluence of the steel will induce tension in the latter while theconcrete itself goes into compression. At the end of moist curing,when the element is exposed to drying conditions, it will shrink1ike a normal Portland cement concrete.

第33页：练习二 参考译文

EXERCISEⅡ. Translation answer

水泥水化后，会形成大量的钙矾石。当混凝土凝固，强度开始发展的时候，如果有足够数量的养护水存在的情况下，混凝土将会粘结钢筋，同时开始膨胀。既然钢筋和混凝土粘结在一起，后期，在钢筋的抑制作用下混凝土膨胀将会产生拉力，然而混凝土本身也受压。在潮湿养护的最后，当构件被暴露在干燥的条件下，将会像普通硅酸盐水泥混凝土一样产生收缩。

第34页：Section C 混凝土耐久性

Chapter 3 Structure MaterialsSection C Durability of Concrete

第35页：耐久性设计趋势

At present, more and more destructive case of engineering due tolack of durability not insufficient strength under all kinds of seriousconditions and many new questions companying with thedevelopment of concrete technology make people pay attention to thedurability of concrete.

现今，在各种严酷环境条件下和伴随许多混凝土技术发展新问题的出现，越来越多的由于缺乏耐久性而不是强度不足的工程破坏实例引起了人们对混凝土耐久性的关注。

The idea of which concrete should be design according todurabilityinstead of strength was accepted widely.

根据耐久性设计代替强度设计的观点越来越广泛地被人们所接受。

第36页：混凝土耐久性的定义

The durability of concrete can be defined as its resistance todeteriorationresulting from external and internal causes.

混凝土的耐久性被定义为抵抗外部和内部原因导致的恶化的能力。

The internal causes are the effects of salts, particularlychloridesandsulphatesin the constituent materials, interaction between theconstituent materials, such asalkaliaggregate reaction, volumechanges,absorptionandpermeability.

内部原因是盐的影响，特别是氯化物和硫酸盐，以及组成材料之间的相互作用，如碱骨料反应、体积变化、吸水性和渗透性。

第37页：材料组分与配合比

In order to produce a durable concrete care should be taken toselect suitable constituent materials.

为了生产高耐久性的混凝土，人们应该注意选择合适的材料组分。

It is also important that the mix contains adequate quantities ofmaterials in proportions suitable for producing ahomogeneousand fully compacted concrete mass.

为生产均匀致密的混凝土，使各组分材料配比得当，这一点也是很重要的。

第38页：冻融与温湿交替破坏

Deterioration of concrete by weathering is usually brought about by thedisruptiveaction of alternate freezing andthawingof free water within theconcrete and expansion and contraction of the concrete, under restraint,resulting from variations in temperature and alternate wetting and drying.

由气候带来的混凝土的劣化通常是由混凝土内部自由水的冻融交替、温变异和干湿交替引起的抑制作用下混凝土的膨胀、收缩等引起的。

Damage to concrete from freezing and thawing arise from the expansionof pore water during freezing, in a condition of restraint, if repeated asufficient number of times, this results in the development of hydraulicpressure capable of disrupting concrete.

在冻期，由冻融循环导致的混凝土破坏是由孔隙水的膨胀引起的，在一个特定条件的限制下，如果冻融循环重复足够的次数，会导致水压力的发展有可能破坏混凝土。

第39页：低水灰比与引气剂

This can be achieved by using a mix with the lowest possible watercement ratiocompatiblewith sufficientworkabilityfor placing andcompacting into a homogenous mass.

高渗透性的混凝土采用较低的水灰比和较好的和易性通过浇注并压实成均匀的实体来得到。

Durability can be further improved by using air entrainment, an aircontent of 3 to 6 percent of the volume of concrete normally beingadequate for most applications.

混凝土的耐久性可以通过采用引气剂进一步改善，通常3%~6%混凝土体积的含气量可以满足应用。

第40页：混凝土的化学侵蚀

There are several chemical agents, which react with concrete, butthe most common forms of attack are those associated withleaching,carbonation, chlorides and sulphates (Fig.

3.1).很多化学制剂会与混凝土发生反应，但最常见的侵蚀是指那些与浸出，碳化，氯化物和硫酸盐（如图3.1）相关的。

Chemical agents essentially react with certain compounds of thehardenedcement paste(水泥浆)and the resistance of concrete tochemical attack, therefore can be affected by the type of cementused.

化学剂本质上与一定数量的硬化水泥浆发生反应，因此，混凝土的耐化学侵蚀能力通常受水泥标号的影响。

第41页：混凝土的磨损

The main causes of wear of concrete arecavitationeffects of fast-moving water,abrasivematerial in water, wind blastingandattritionand impact of traffic.

混凝土磨损的主要原因是由快速流动的水、水里的磨损材料、风沙袭击和磨耗以及交通的影响。

Since even a good-quality concrete will not be able to resist thiskind of deterioration, the best remedy is therefore the elimination ofcavitation by producing smooth hydraulic flow.

即使很好质量的混凝土都无法抗拒这种劣化，因此，最好的补救办法是通过制造光滑的液压流来消除气穴。

第42页：体积变化与火山灰反应

Principal factors responsible for volume changes are the chemicalcombination of water and cement and the subsequent drying ofconcrete, variations in temperature and alternate wetting and drying.

对于体积的改变主要的影响因素是水和水泥的化学结合、随之而来的混凝土干燥以及温度的变异和干湿交替。

In the case offly ash(粉煤灰)orsilica fume(硅粉)mixed in theconcrete, activation composition ofmineral admixtureandcalciumhydroxide(氢氧化钙)precipitation of cement hydrate have pozzolanicreaction and generate calcium silicate, which expands in volume( Fig.

3.2) .当粉煤灰等矿物掺合料掺入混凝土时，其活性成分与水泥水化析出的氢氧化钙发生火山灰反应，生成体积胀大的硅酸钙水化物（如图3.2）。

第43页：裂缝与耐久性下降

When change in volume is resisted by internal or external forces,this can produce cracking, the greater the imposed restraint, themore severe the cracking.

当混凝土体积的改变被内部或外部力抑制时，这将会产生裂缝，越是抑制，裂缝就越严重。

The presence of cracks in concrete reduces its resistance to theaction of leaching, corrosion of reinforcement, attack by sulphatesand other chemicals, alkali-aggregate reaction and freezing andthawing, all of which may lead to disruption of concrete.

混凝土中裂缝的存在降低了它对浸析、钢筋锈蚀、硫酸盐和其他化学物质侵蚀、碱骨料反应和冻融损伤的抵抗力，从而导致混凝土破坏。

第44页：混凝土的渗透性

Permeability refers to the ease with which can pass through theconcrete. This should not be confused with the absorption property ofconcrete and the two are not necessarily related.

渗透性指水透过混凝土的难易程度，不能与混凝土的吸水性相混淆，这两者不一定相关。

Low permeability is an important requirement for hydraulicstructures and in some cases water tightness of concrete may beconsidered to be more significant than strength although, otherconditions being equal, concrete of low permeability will also bestrong and durable.

对于水工结构，低渗透性是一个很重要的要求，在某些情况下，可以认为混凝土的不透水性比强度更为重要。

其它条件相同的情况下，混凝土的低渗透性将会使其更耐久。

第45页：和易性与孔隙连通

This arises from the use of water in excess of that required for thepurpose of hydration in order to make the mix sufficiently workableand the difficulty of completely removing all the air from concreteduring compaction.

混凝土在拌和过程中和易性良好而使水化充分，需要加入过量的水，这样在捣实过程中空气难以完全从混凝土中排出。

If the voids are interconnected concrete becomes perviousalthough with normal care concrete is sufficiently impermeable formost purposes.

尽管用于工程目的正常养护的混凝土具有足够的不透水性，但是如果这些孔洞是相连通的，那么混凝土变得很容易被渗透。

第46页：离析与系统评估方法

Segregationof the constituent materials during placing canadversely affect the impermeability of concrete.

在浇注过程中，组成材料的离析会严重影响混凝土的抗渗性能。

It is pointed out that system theory method is favorable forresearching the concrete durability and its evaluation withperformance, structure, process and environment as a whole.

将性能、结构、过程和环境等作为一个整体的系统论方法来评估混凝土的耐久性被证明是有效的。