考虑轴压比、剪跨比、配筋率等不同参数的变化,设计一组端部带施工缝的钢筋混凝土柱进行低周反复荷载试验。观察试件的破坏形态并与无缝柱对比,发现施工缝对柱端传力机制和破坏机理均有影响,会造成应力集中,使塑性铰长度变小,沿施工缝的滑移使塑性铰区剪切变形增大。试验中测量了施工缝周围的剪切变形,得到剪力-剪切变形滞回曲线。分析各个参数对剪切滞回曲线的影响,发现轴压比增大使受剪承载力提高而使延性降低;剪跨比减小使剪切变形分量增大,同时使滞回曲线由梭形变为反S形。回归得出二折线骨架曲线的分段计算式,并在综合现有剪切恢复力模型研究成果基础上确定加卸载规则,给出了带施工缝钢筋混凝土柱截面剪切恢复力模型。对带施工缝试件进行数值计算,力-位移滞回曲线的计算结果与试验吻合良好,验证了模型的有效性。 Considering the changes of different parameters such as axial compression ratio, shear span ratio and reinforcement ratio, a series of reinforced concrete columns with construction joints at the ends were designed for low-cycle cyclic loading tests. The failure mode of the specimen was observed and compared with that of the seamless column. It was found that the construction joint had an effect on the force transmission mechanism and the failure mechanism at the column end, which resulted in stress concentration and decreased plastic hinge length. Sliding along the construction joint made the plastic hinge Area shear deformation increases. In the experiment, the shear deformation around the construction joint was measured and the shear deformation-hysteresis curve was obtained. The influence of each parameter on the shear hysteretic curve is analyzed. It is found that the increase of axial compression ratio leads to the increase of shear bearing capacity and the decrease of ductility. The decrease of shear span ratio increases the shear deformation component and the hysteresis curve changes from fusiform to Anti-S-shaped. The regression formula of the two-fold line skeleton curve is deduced, and the rules of loading and unloading are determined based on the research results of the existing shear restoring force model. The shear restoring force model of reinforced concrete column with construction joints is given. The numerical results of the specimens with construction seams show that the calculated results of the force-displacement hysteresis curve are in good agreement with the experimental results, which verify the validity of the model.