考虑箍筋约束的HRB500级纵筋柱抗震性能试验研究

通过对各国规范中柱子箍筋加密区的构造对比,发现中国规范与国外规范在配箍特征值的取值上有较大差别。此外,在钢筋混凝土柱中采用更高强度的HRB500钢筋后,按照GB 50010—2010《混凝土结构设计规范》设计的柱子其抗震性能是否能达到要求也需进行验证。通过对9根配置HRB500纵筋柱进行低周反复荷载试验,分析配箍率、配箍特征值、箍筋强度以及配箍形式等因素对柱的破坏状态、P-Δ滞回曲线、延性、刚度退化以及耗能能力的影响;对比分析条件基本相同情况下配置HRB500纵筋柱与配置HRB335纵筋柱受力性能的差异。研究结果表明,当柱端箍筋加密区的构造满足要求时,配置HRB500纵筋柱能够满足抗震结构对柱的变形能力以及位移延性的要求。

EXPERIMENTAL STUDIES ON SEISMIC BEHAVIORS OF RC COLUMNS WITH HRB500 LONGITUDINAL REINFORCEMENTS CONSIDERING CONFINEMENT OF STIRRUPS

In the specifications on detailing of stirrups and minimum hoop characteristic factors in column hoop densified regions,there exists large difference between Chinese Codes and related codes of other countries.So it is necessary to check the seismic behaviors of columns with different transverse reinforcement schemes in different codes.Moreover,it is needed to verify the seismic behaviors of columns designed to Chinese Codes using HRB500 rebars with a higher strength as longitudinal reinforcements.Reverse cyclic loading tests of 9 RC column specimens reinforced with HRB500 rebars were conducted.The test parameters included the transverse reinforcement ratio,hoop characteristic value,stirrup strength and arrangement of stirrups.The effects of these parameters on the failure mechanism,load-deflection hysteretic-curve,ductility,stiffness degradation and energy-dissipating capacity were analyzed.Different behaviors between the columns with HRB500 rebars and those with HRB335 rebars were discussed,with other parameters remaining the same.The results showed that when the details of stirrups in hoop densified regions confirming to the design codes,the columns reinforced with HRB500 rebars could meet the seismic requirements of deformability and ductility.