【摘要】 为研究再生混凝土框架柱的抗震性能,对剪跨比为4、截面尺寸为450 mm×450 mm的6根再生混凝土柱和1根普通混凝土柱进行低周反复荷载试验.试验参数主要为纵筋率、轴压比、箍筋加密区的体积配箍率,其中配箍率的取值与国家规范的要求接近.结果表明,低轴压、低配箍的再生混凝土柱可实现良好的延性和变形性能,能满足抗震设计的要求;较高轴压、低配箍的再生混凝土柱最终发生剪切压溃,呈现出显著的脆性性质;较高轴压的再生混凝土柱在提高配箍后,延性与耗能性能得以改善.建议轴压比不宜过大,并适当提高配箍要求.此外,分析表明再生混凝土柱极限受弯承载力的计算可采用与普通混凝土柱类似的方法,通过考虑钢筋强化、合理选取再生混凝土的本构模型进行准确计算.更多还原

【Abstract】 To study the seismic behavior of recycled concrete frame columns,six recycled concrete columns and one normal concrete column are tested under low-cycle reversed loading.The columns are 450 mm×450 mm in cross section and the shear span ratio is 4.The test parameters mainly include longitudinal steel ratio,axial load ratio and stirrup reinforcement ratio in potential plastic region.In this test,the stirrup reinforcement ratios of columns are close to the limit requirements of Chinese code.The experimental results show that the columns with small axial load and low stirrup reinforcement ratio can achieve satisfactory ductility and ultimate deformability,which can meet the requirements of seismic design.However,the columns with high axial load and low stirrup reinforcement ratio exhibit obvious brittle behavior and the shear crushing is observed at final failure.After improving the stirrup reinforcement ratio of the columns with high axial load,its ductility and energy dissipation behavior become better.It is recommended that the axial load ratio should not be too large,and the confinement requirement should be improved.Moreover,analyses show that the calculation of the ultimate flexural capacity of recycled concrete columns can use similar method to that of normal concrete columns,and it can be accurately calculated by considering the strain hardening of longitudinal steel and appropriately choosing the stress-strain model of recycled concrete.更多还原