| Summary: | 碩士 === 國立臺灣大學 === 土木工程學研究所 === 106 === The modulus of elasticity of concrete, Ec, is an important factor in design of RC structures. Modulus of elasticity is also essential for engineers to estimate deflections and stiffness of RC members. In Taiwan, due to the soft nature of coarse aggregates and high amount of paste in concrete mix designs, the prediction of Ec calculated by current design code is usually overestimated by 20% of that obtained by experimental results..The revision of Ec (=12000 f''c^0.5, which is 80% of current Ec =15000 f''c^0.5) has been submitted to the government authorities and under further review to reflect this occurrence. The reduction of Ec would affect design codes in Taiwan, such as “Design Code for Concrete Structures”, “Seismic Design Specifications and Commentary of Buildings” and “Allowable Stress Design Specifications and Commentary of Steel Structures”. The objectives of this research are to clarify those influences on design code for structural concrete, to investigate the nonlinear responses of different story hight buildings with reduced Ec and to comment and summarize these observations to the engineering society.
The results show that the minimum thickness of reinforced concrete slab and number of shear concrete stud should be increased because of the reduction of Ec. In addition, even though seismic and collapse capability of Experimental Frames (0.8 Ec) slightly decrease according to nonlinear analyses, all of them still meet the requirements of current seismic design codes in Taiwan.
|
|---|
