钢筋混凝土结构通常承受使用荷载且带裂缝工作,持续荷载和裂缝对钢筋混凝土结构滞回性能影响的情况尚不清楚。通过对养护28 d后的钢筋混凝土柱施加不同比例的大偏心受压持续荷载,在大气环境下养护100 d(总计128 d),卸掉持续荷载,进行低周期反复加载试验,以探讨持续荷载和裂缝对滞回性能的影响。结果表明,当持续荷载与低周反复荷载产生的应力分布一致时,钢筋混凝土柱的初始加载刚度、极限荷载和延性随持续荷载增大而降低;反之,极限荷载随持续荷载增大而降低,初始加载刚度和延性随持续荷载增大呈增大的趋势,但不够显著。说明持续荷载对钢筋混凝土柱的滞回性能有一定影响。
Reinforced concrete structures in service are usually with cracks and subjected to the service load,the hysteretic behavior of reinforced concrete structures with sustained eccentric loads and cracks needs to be investigated.The 28 d cured reinforced concrete columns with different sustained compressive eccentric loads were cured in the nature condition for 100 d,then their hysteretic behaviors were tested after the sustained loads were removed.Results showed that when the horizontal load produced the same tensile and compressive stress distribution as that of sustained eccentric load,the ultimate loads,ductility and initial stiffness of columns decreased with the increase of sustained eccentric loads.When the horizontal load was reverse,the ultimate loads showed an descend trend,while the initial stiffness and ductility increased with increase of sustained eccentric loads.The sustained eccentric loads had an impact on the hysteretic behavior of reinforced concrete columns.