Influence Of Material Characteristics On Ductility Of Concrete Member

Reinforced concrete member having good ductility is premise to ensure sturcture having good ductility, so studying member ductilitity has important significance. At present, researchers of all countries study large quantities of analysis on factors that affect member ductility, summarizing relationship between each factor and ductility and putting forward measures to ensure member having good ductility. But a little time spends on researching requirements of percentage elongation of rebar to insure member having certain ductility and whether member ductility exsiting size effect or not.Based on theoretical analysis and large quantities of experimental data collected, this paper analyzes requirements of percentage elongation of rebar to appropriately reinforced beam with singly reinforced rectangular sections, doubly reinforced rectangular sections and flanged sections. According to basic assumptions of code for design of concrete structures of our country, calculation formula of section curvature ductility coefficient and displacement ductility coefficient are deduced. Requirements of percentage elongation of rebar are put forward for ensuring sections having certain curvature ductility coefficient and members having certain displacement ductility coefficient. Calculation formula of length of equivalent plastic hinge of reinforced concrete flexural members and compression-flexure members which are put forward by researchers of all are summaried. Whether length of equivalent plastic hinge exsits size effect or not is analyzed. In addition, this paper sums up main factors effecting ductility and adopted measures in codes to ensure member having certain ductility.Finally, the conclusions of this paper are summaried and the problems requiring further studies are discussed.