《混凝土结构设计原理》双语 (11).ppt

Theory of reinforced concrete members钢筋混凝土基本原理 主讲教师：杨维汉 Email: 498107@163.com 理 论 基 础 Main kinds of structures Reinforced concrete (R.C.) Steel structure Wood structure Membrane structure Introduction (1class) What is R.C Why select steel bar? The modulus of elasticity; the ductility; yield strength; rupture strength must be considerably higher than those of concrete in order to raise the capacity of the reinforced concrete section to a considerably high level (tensile strength /compressive strength≈1/10) The compatibility of the two material to work “together” in existing of the external load. Reinforcing bar has to undergo the same strain or deformation as the surrounding concrete in order to prevent the discontinuity or separation of the two materials under load Similar linear expansion factor (Steel 1.2×10-5, concrete 1.0～1.5×10-5) Materials such as brass, aluminum, rubber and bamboo are not suitable for developing the bond and adhesion necessary between the reinforcement and concrete. Steel and fiberglass do process the principle factors above Steel member has the problem of stability under compression Compatibility （变形协调） Reinforcing bar has to undergo the same strain or deformation as the surrounding concrete in order to prevent the discontinuity or separation of the two materials under load Similar linear expansion factor（线膨胀系数） (Steel 1.2×10-5, concrete 1.0～1.5×10-5) Brass, aluminum, rubber and bamboo Example 1-1: Ultimate load carrying capacity of plain concrete beam and R.C. beam 150×300mm2 section, 3000mm long History of reinforced concrete Middle of 20’century History of reinforced concretein China 1889 开始了水泥工业 1908 上海电话公司是中国最早的钢筋混凝土框架结构 Characteristics of the present text Emphasis on inherent mechanism Comparison between different building codes * 材料力学 建筑材料 结构力学 Cure（养护）: Accelerate chemical hydration reaction between Water/Cement Cement, Water, Fine（细） aggregate（骨料）, Coarse（粗） aggregate, Air and other admixtures Pour Plastic Mixt