第1章 混凝土结构用材料的性能（Chapter 1. Properties of concrete structures used in materials）In this paper, by foot Tian snake contributionThe PPT document may not have a good browsing experience at the WAP end. It is recommended that you choose TXT, or download the source file to the native view.Chapter 1 material properties of concrete structureThe concrete structure is made of reinforced concrete and concrete. In order to properly design the concrete structure. In order to design the concrete structure reasonably, the stress performance of concrete and steel reinforcement is needed. Understand the mechanical properties of concrete and steel. The solution of the mechanical properties, interaction and common work of concrete and steel mechanics, soil and steel, is the basis of the analysis and design of concrete structure components. Basis of analysis and design. 1 bar1.1 the varieties and properties of steel a, classification According to the machining method points: 1. According to the processing method: hot rolled steel, heat treatment in steel, high strength steel wire, steel strand in the steel, hot rolled steel, heat treatment, high strength steel wire, steel strand, cold working steel bar By using utility cent: ordinary reinforced, (2) according to the using purpose: ordinary reinforced, prestressed reinforcement According to chemical composition points: low carbon steel, (3) according to the chemical composition points: low carbon steel and ordinary reinforced according to the mechanical properties of low alloy steel, steel has obvious yield point, 4. According to the mechanical properties of points: have obvious yield point steel, no significant yield Some steel According to the steel shows that shape points: plain bar, 5. According to the steel shows that shape points: smooth steel and deformed steel(1) hot rolled steel hot-rolled steel hot rolled steel is steel with ordinary low carbon steel (carbon content is not greater than 0.25 hot rolled steel mills with ordinary low carbon steel carbon content is not more than and ordinary low alloy steel (alloy elements made. No more than %) and ordinary low alloy steel alloying elements is not more than %). And ordinary low alloy steel alloy elements are not greater than 5%The hot rolled steel is divided into I, II, III and IV, respectively, according to its carbon content.The commonly used types are shown. The commonly used types, symbols and diameters are shown in table 1-1. As shown inThe type of hot rolled steel, the type of hot rolled steel, the symbol and diameter range are usedStrength grade code HPB235 HRB335 HRB400 RRB400D/mm6 20, 20, 6 50, 50, 6 50, 8 40Q235 (low carbon steel) Q235 (low carbon steel) 20MnSi (low alloy steel) 20MnSi (low alloy steel) 20MnSiV, 20MnSiNb, 20MnTi low alloy steel) (low alloy steel) K20MnSi (low alloy steel) K20MnSi (low alloy steel)For hot rolling plain bar, HPB235 for hot rolled smooth steel, ordinary steel hot rolled deformed bars, HRB335 and HRB400 hot rolled deformed bars, ordinary reinforced RRB400 is steel heat treatment steel heat treatment is the yield strength of steel bar in wear water cooling after rolling, HRB335 rebar in water cooling after rolling, then using the core residual heat quenching water scale on the surface of steel and deformed steel tempering treatment. The hardened steel surface of the rebar and the hardened steel. Its performance is close to the steel bar,The grade steel bar is stable, and the steel bar of HRB400 is not equal to that of the HRB400 steel bar, but the strength of the steel reinforcement is reduced, so the application scope is limited. The strength of the reinforcement is reduced, so the application scope is limited.In the construction of highway bridge, it is said that in the construction of highway bridge, the steel bar of hot rolled face is used for R235, and the residual heat processing steel is indicated by KL400. The diameter of the steel bar does not indicate that the steel mills of any diameter in this range are produced. Steel mills are produced. Steel bar diameter is 6 mm, 6.5 mm, 8 mm, 8.2 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm and 22 mm, 25 mm, 28 mm, 32 mm, 36 mm, 40 and 50 mm, mm. In this case, d = 8.2 mm steel bar only applies to steel design with longitudinal ribs. In the design, choose the steel bar in the diameter of table 1-1 and the diameter provided above. The reinforcement is mainly used for the selection of reinforcement. The steel bar with diameter greater than 40 mm is mainly used in a large concrete structure of the dam. In the concrete structure. When using a steel bar with a diameter greater than 40 mm, it should be able to rely on engineering experience. Working experience in engineering.Strength of reinforcement and deformation can be obtained by tensile test stress - strain curveTensile test of reinforcementPa.P = A sigmalL epsilon = lPThere i