土木工程材料—2010

1、土木工程材料土木工程材料 任何土木工程建（构）筑物（包括道路、 桥梁、港口、码头、矿井、隧道等）都是用材 料按一定的要求打造成的，土木工程中所使用 的各种材料都统称为土木工程材料。 长期以来人类一直在从事着土木工程材料 的各类研究工作，并不断开发新的材料。几乎 世界上的各种材料都可用作土木工程材料。 2.1 传统土木工程材料 2.1.1 砖 砖的分类： 标准砖 多孔砖 砌块 砖 建筑用的人造小型块材分烧结砖建筑用的人造小型块材分烧结砖 （主要指粘土砖）和非烧结砖（灰（主要指粘土砖）和非烧结砖（灰 砂砖、粉煤灰砖等），俗称砖头。砂砖、粉煤灰砖等），俗称砖头。 1、按材质分：粘土砖、页岩砖、煤矸石

2、砖、粉煤灰砖、灰 砂砖、混凝土砖等。 2、按孔洞率分：实心砖(无孔洞或孔洞小于25%的砖)、多孔 砖(孔洞率等于或大于25%，孔的尺寸小而数量多的砖，常 用于承重部位，强度等级较高。) 3、空心砖(孔洞率等于或大于40%，孔的尺寸大而数量少的 砖，常用于非承重部位，强度等级偏低。) 4、按生产工艺分：烧结砖(经焙烧而成的砖)、蒸压砖、蒸 养砖。 5、按烧结与否分为：免烧砖（水泥砖）和烧结砖（红砖） 瓦是屋面材料。瓦是屋面材料。 2.1.2 瓦 波兰波兰 2.1.3 2.1.3 石材石材 凡采自天然岩石，经过加工或未 经加工的石材，统称为天然石材。 石的种类： 1、毛石 2、料石 3、饰面石材

3、4、色石渣 石子石子 2.1.4 2.1.4 砂砂 砂一般分为：天然砂和 人工砂。 由自然条件作用（主要 是岩石风化）而形成，粒 径在5 mm以下的岩石颗粒， 称为天然砂。 人工砂是由岩石轧碎而 成，由于成本高、片状及 粉状物多，一般不用。 砂的粗细程度是指不同粒径的砂粒混合在一起 的平均粗细程度。通常有粗砂、中砂、细砂之分。 黄砂 2.1.5 2.1.5 灰灰 灰是指石灰和石膏。也指水泥. 石灰和石膏是无机胶凝材料。 2.1.6 2.1.6 木材木材 影响木材强度的主要因素为含水率（一般含水率高， 强度降低），温度（温度高，强度降低），荷载作用时间 （持续荷载时间长，强度下降）及木材的缺陷（

4、木节、腐 朽、裂纹、翘曲、病虫害等）。 木材的主要性质： 木材的性质包括物理性质和力 学性质，如含水率、热胀干缩、密 度、强度(抗拉、抗压、抗弯和抗 剪等四种强度)，其中抗拉、抗压、 抗剪强度又有顺纹和横纹之分。顺 纹和横纹强度有很大的差别。 2.2 近代土木工程材料 2.2.1 钢材 一、钢材的分类一、钢材的分类 建筑钢材的产品种类一般分为型材、 板材、管材和金属制品四类。 2.2.1 2.2.1 钢材钢材 1 1、型材、型材 主要有角钢、工字钢、槽钢、方钢、吊车轨道、金属门窗、 钢板桩型钢等。 槽钢槽钢 钢钢 管管 角钢角钢 工字钢工字钢 H型钢型钢 2.2.1 2.2.1 钢材钢材 2、

5、板材 主要指钢结构用钢，建筑结构中主要采用 中厚板与薄板。 3、管材 主要用于桁架、塔桅等钢结构中。 4、金属制品 土木工程中主要使用的产品有钢丝、钢丝 绳以及预应力钢丝及钢绞线。 二、土木工程用钢材二、土木工程用钢材 土木工程钢材可划分为钢结构用材和钢筋混凝土用材两大类。土木工程钢材可划分为钢结构用材和钢筋混凝土用材两大类。 1 1、钢结构用钢材、钢结构用钢材 我国钢结构用钢材的钢 类主要有普通碳素结构钢和 低合金结构钢。主要有 Q235(A3钢)、Q315(16Mn钢) 轻钢厂房 2.2.1 2.2.1 钢材钢材 2 2、钢筋混凝土用钢材、钢筋混凝土用钢材 钢筋混凝土用的钢材主要指钢筋。

6、钢筋等级： 一级钢 二级钢 三级钢 四级钢 二级钢二级钢 一级钢一级钢 2.2.1 2.2.1 钢材钢材 钢筋钢筋 2.2.1 2.2.1 钢材钢材 2.2.2 2.2.2 水泥水泥 1、水泥的定义、水泥的定义 水泥是粉状 的水硬性胶凝材 料，即加水拌合 成塑性浆体，能 在空气中和水中 凝结硬化，可将 其它材料胶结成 整，并形成坚硬 石材的材料 。 袋装水泥袋装水泥 2 2、水泥的定义和分类、水泥的定义和分类 (1)水泥按其用途及性能分为三类： 通用水泥, 专用水泥, 特性水泥。 (2)水泥按其主要水硬性物质名称分为： 硅酸盐水泥，铝酸盐水泥，硫铝酸盐水泥， 氟铝酸盐水泥，磷酸盐水泥，以火山灰

7、性或 潜在水硬性材料以及其他活性材料为主要组 分的水泥。 2.2.2 2.2.2 水泥水泥 2.2.3 2.2.3 混凝土混凝土 一、一、混凝土混凝土 简写砼，是当代最主要的土木工程材料之一。简写砼，是当代最主要的土木工程材料之一。混凝混凝 土是由胶结材料，骨料和水按一定比例配制，经搅拌振土是由胶结材料，骨料和水按一定比例配制，经搅拌振 捣成型，在一定条件下养护而成的人造石材。捣成型，在一定条件下养护而成的人造石材。 二、发展历史二、发展历史 18241824年年AspdinAspdin发明了波特兰水发明了波特兰水 泥（硅酸盐水泥），以水泥作为胶泥（硅酸盐水泥），以水泥作为胶 凝材料的混凝土开

8、始问世凝材料的混凝土开始问世 18501850年钢筋混凝土问世年钢筋混凝土问世 19281928年预应力混凝土问世年预应力混凝土问世 混凝土运输车 商品砼商品砼 预拌商品混凝土生产企业应当建立和完 善预拌商品砼生产的质量保证体系,制 定必要的技术管理和质量检查制度。 建立.材料应当由预拌商品混凝土生 产企业自行采购,任何单位不得.工 程交工时,有关商品混凝土生产、使用 应提供以下资料: . 2.2.3 混凝土 1、普通混凝土 (1)普通混凝土是由水泥、粗骨料（碎石或 卵石）、细骨料（砂）和水拌合，经硬 化而成的一种人造石材。 (2)砂、石在混凝土中起骨架作用，并抑制 水泥的收缩； 水泥和水形成

9、水泥浆， 包裹在粗细骨料表面并填充骨料间的空 隙。水泥浆体在硬化前起润滑作用，使 混凝土拌合物具有良好工作性能，硬化 后将骨料胶结在一起，形成坚强的整体。 三、混凝土的种类三、混凝土的种类 2.2.3 2.2.3 混凝土混凝土 2.2.3 2.2.3 混凝土混凝土 2 2、特种混凝土、特种混凝土 (1) 轻集料混凝土（轻质砼、轻骨 料砼）、 (2) 纤维增强混凝土（简称FRC） (3) 聚合物混凝土 (4) 道路混凝土（碾压砼） (5) 自密实混凝土 2.2.3 2.2.3 混凝土混凝土 3 3、钢筋混凝土与预应力钢筋混凝土、钢筋混凝土与预应力钢筋混凝土 钢筋混凝土是指配置钢筋的混凝土。 预应

10、力混凝土一般指预应力钢筋混 凝土。 2.3 2.3 现代土木工程材料现代土木工程材料 2.3.1 2.3.1 沥青、沥青制品与其他防水材料沥青、沥青制品与其他防水材料 地沥青（包括天然地沥青和石油地沥青） 焦油沥青（包括煤沥青、木沥青、页岩沥青等） 沥青复合胎柔性防水卷材 2.3 2.3 现代土木工程材料现代土木工程材料 2.3.2玻璃、陶瓷制品 2.3.3人造板材 2.3.4塑料及制品 2.3.5绝热材料 2.3.6吸声隔声材料 2.3.7装饰材料 2.3.8新型复合板材 2.3.9绿色建材 位于北京天安门广场西侧的国家大剧院东西跨度212米，整个结构 不用一根柱子支撑，而全靠弧形钢梁来承受

11、巨大重力 国家大剧院设计者保罗国家大剧院设计者保罗安德鲁安德鲁 在建中的沙州钢铁厂钢结构厂房在建中的沙州钢铁厂钢结构厂房 北京电视中心工程北京电视中心工程： 它是2008年北京奥运 会配套项目。建成后 它将成为长安街标志 性建筑和北京最高的 纯钢结构建筑（高 236）。 课外检索课外检索 1、列举有代表性的采用不同建筑材料 的典型建筑。 2、绿色建材全面系统研发的含义。 土木工程概论土木工程概论 土木工程概论 Introduction to Civil Engineering 第二章土木工程材料第二章土木工程材料 Chapter 2 Materials for Civil Engineerin

12、g Materials for Civil Engineering What is Materials of Civil Engineering? It covers the development, processing, evaluation, applications, and performance of construction materials in civil engineering. Wide varieties of materials are used for making engineering structures and buildings. It is neces

13、sary for an engineer to have a basic knowledge of these materials which are available either from natural resource or manufactured. Stones: Stones are used in Civil Engineering constructions in different forms. Stone blocks irregular in size called rubbles are used for building walls. Smaller irregu

14、lar stones are used for constructing the base of floors and roads. Stones broken into smaller pieces are called aggregates. Stones required in these ways are obtained from rocks. Materials for Civil Engineering Bricks: Common building bricks are rectangular solids, made of burnt clay. The earth used

15、 for the manufacture of bricks should contain 2030% of clay, 2540% of sand and 2535 % of silt. The manufacture of bricks involves the following four operations: 1. Preparation of clay 2. Moulding 3. Dry 4. Burning Materials for Civil Engineering Uses of bricks: The construction of walls to carry the

16、 loads from roofs to the foundation To construct walls for partitioning a room or enclosing an area The construction of gutters, drains and arches Hollow bricks are used for sound and heat insulation purposes Fire bricks are used for insulating chimneys and ovens Facing bricks are used for ornamenta

17、l purposes Sometimes, bricks are used for paving of footpaths or industrial floors Materials for Civil Engineering Cements: Even in 100 BC, Roman builders used a special volcanic ash for cementing stones. When this ash was mixed with limestone, burnt and combined with water, it became a very strong

18、cement. The builders found this cement would harden with water. Hence, it was called Hydraulic cement. Materials for Civil Engineering Uses of cements: To make cement mortar and cement concrete Wide varieties of purposes staring from ordinary foundation to roofs of multistory skyscrapers Sulphate re

19、sisiting cement is used to protect the foundations and other components in contact with the earth against the chemical action of sulphate in the soil Rapid hardening cement and early strength cement have been used in works which need early strength gain like chimneys and underwater concreting White

20、and colored cements are used for making ornamental plastering and floor finish Materials for Civil Engineering Concrete: When stone or gravel, sand, cement and water are mixed together, they form an easily workable plastic mixture which can be moulded and cast into desired shapes or structures. This

21、 cement and water in the plastic mixture undergo a chemical combination in a few hours after the mixing results in a solidification and gradual hardening. This mixture is called concrete. Materials for Civil Engineering Concrete: Concrete is a structural material which consists of Portland cement, a

22、ggregate (sand and rock), and water (to make the chemical reaction called hydration occur). Concrete can sometimes contain other substances, such as fly ash from industrial smoke stacks, which can change its properties. Materials for Civil Engineering Concrete: Concrete is a very strong material whe

23、n it is placed in compression. It is, however, extremely weak in tension. It is for this reason that we use reinforcement in concrete structures. The reinforcement, which is usually steel, takes up the slack for the weakness of the concrete in tension. Materials for Civil Engineering Concrete: There

24、 are many ways to test the strength of a batch of concrete. The tests used can be categorized as destructive and nondestructive tests. We will perform both types of tests in this class. Materials for Civil Engineering Concrete: Usually when a batch of concrete is ordered on a job site it is specifie

25、d to be of a specific compressive strength 4 000 psi, for instance. When the concrete comes to the job site in a ready-mix truck, the contractor places some of the batch in cylinders which are 6 inches in diameter and 12 inches in height. Materials for Civil Engineering Concrete: These cylinders are

26、 cured for 28 days and tested by compression until they are crushed. This will give the contractor or the engineer the compressive strength for that batch of concrete. He or she can then compare that value to the design value used to make sure that the structure was constructed properly. Materials f

27、or Civil Engineering Concrete: Once the concrete has been placed for a particular structure, there is a nondestructive test which can be performed to estimate the strength of the concrete. This method uses a Schmidt hammer (also called a Swiss hammer). This method of testing is based on the inertia

28、of a ball inside the Schmidt hammer testing apparatus that is bounced off of the concrete. Materials for Civil Engineering Concrete tests: Each group will perform two tests on a concrete cylinder. The first test will be the Schmidt hammer test. Each person in the group will take a turn using the Sch

29、midt hammer and the results of the group members will be averaged. Each group will then take their cylinder into the structures lab where it will be tested to crushing in a compression testing machine. Materials for Civil Engineering Concrete strength: Concrete and steel are the most widely used mat

30、erials in engineering design. Concrete is very important material for the civil engineer designing because steel is not readily available and can be very expensive to bring to the site. Materials for Civil Engineering Concrete strength: Some advantages of using concrete in design are as follows: hig

31、h fire and weather resistance, relatively low cost (most of the materials can be obtained locally), can be poured to fit odd shapes (good for unusual architectural designs). As you drive down I-75, I-4, or on the turnpike you will notice that almost all the bridges are constructed of concrete. Mater

32、ials for Civil Engineering Concrete strength: As you walk around Weil Hall (the building you are in now) you will notice that the beams and columns are made of concrete. The new South End zone for the University of Floridas Football Stadium and the new addition to the commuter parking garage were co

33、nstructed using concrete.These are just a few examples. Materials for Civil Engineering Concrete strength: Concrete is composed of four ingredients: cement, sand, aggregate (stones, gravel, etc.), and water. The strength and other properties of concrete are dependent on how these four ingredients ar

34、e proportioned and mixed. The most common type of cement is Portland. Materials for Civil Engineering Concrete strength: Unlike steel, concrete is adequate in strength in only one direction. Concrete is very good in compression but useless in tension. Engineering design is based on concretes compres

35、sive strength. Compressive strength, fc, refers to what concrete is capable of resisting from loads when they are pushing on the concrete (compression). Materials for Civil Engineering Concrete strength: Compressive strengths for concrete are usually in the range of 3 000 to 5 000 psi (pounds per sq

36、uare inch). To correct for the lack of tension strength in concrete, high tensile strength steel is placed in the tension side of concrete. The steel used for reinforcement usually consists of round steel bars often called rebars. When this combination occurs it is called reinforced concrete. Materi

37、als for Civil Engineering Concrete strength: When Civil Engineers design, they obviously need to know the strength of the material that they are using. By knowing the strength of the material that is being used and the loads (forces i.e. people, cars, furniture) that will be acting on the particular

38、 member (beam, column, arch, etc.) the engineer can pick the correct dimensions for the design. Materials for Civil Engineering Concrete strength: In todays lab, two tests will be introduced to check the structural quality of concrete (find its strength). The first test involves loading the concrete

39、 cylinder shown in the drawing until failure. This test is useful for checking the strength of the concrete that is presently being used for a construction site. Materials for Civil Engineering Concrete strength: The American Concrete Institutes Code specifies that a pair of cylinders shall be teste

40、d for each 150 yd3 of concrete or for each 5 000 ft2 of surface area actually placed. This is a quality control measure. Materials for Civil Engineering Concrete strength: The other test that we will conduct in the lab today is called the Schmidt (or Swiss ) Hammer Test . This test gives an estimate

41、 of the concretes compressive strength. This test is performed in situations where the concrete has already been poured and a cylinder test is not possible. Materials for Civil Engineering Concrete strength: If a structural engineer wanted to check a beam for its concrete strength 6 months after the

42、 building had been constructed the engineer might use this test. What are possible sources of error between the two tests and within the tests themselves? Materials for Civil Engineering Steel: Steel is a structural material which consists mostly of iron and carbon. It can, however, contain other ad

43、ditives which might change the steels properties. Steel can be hot rolled or cold formed into structural shapes, such as the familiar I beam known today as a wide flange. Steel has the same strength in tension as it has in compression, unlike concrete. Materials for Civil Engineering Steel: We will

44、perform two tests which can be related to steel. These tests will be a tension test, which can be used to measure the material properties of a steel (or really any material, for that matter), and a beam bending test, which can be used to measure the material properties of a specimen and the effectiv

45、eness of the orientation of the beam. Materials for Civil Engineering Steel: We will be using small aluminum beam specimens to simulate steel beams. The mechanics are the same only aluminum is more flexible than steel, so it is easier to see deflections with aluminum. Materials for Civil Engineering

46、 Steel tests: We will perform the tensile test first. A cylindrical coupon made of steel will be placed in the tensile testing apparatus. The coupon will then be pulled until it breaks. A displacement indicator will be attached to the coupon to take strain readings. From the information gathered fro

47、m this test, we can calculate the modulus of elasticity, the stress experienced by the coupon, and the strength of the steel which made up the coupon. Materials for Civil Engineering Reinforced Concrete: Concrete has a great compressive strength. However, its tensile strength is very low. In reinfor

48、ced concrete, steel and concrete are combined to take advantage of high compressive strength of concrete and high tensile strength of steel. The location of steel within the concrete is important. The tensile area needs steel reinforcement. Materials for Civil Engineering Reinforced Concrete: The lo

49、cation of steel within the concrete is important. The tensile area needs steel reinforcement. Materials for Civil Engineering Timber: Woods are generally classified for construction as hard wood, medium hard wood, and softwood classes. Wood is graded according to natural defects present in the timbe

50、r, like knots and sloping grains. Materials for Civil Engineering What are the forms in which stones are used in Civil Engineering? What are the qualities of good building stones? What are the dimensions of ordinary bricks? What are the general uses of bricks? What is the constituent of concrete? Ex

51、plain in brief the manufacture of cements. What are the uses of cements? Explain the influence of water-cement ratio on the properties of concrete. What is the need for providing reinforcements to a concrete beam? What are the advantages of steel as a construction material? Review Questions Materials for Civil Engineering 2.2 近代土木工程材料 2.2.1 钢材 一、钢材的分类一、钢材的分类 建筑钢材的产品种类一般分为型材、 板材、管材和金属制品