火灾后钢管 RPC 柱抗爆性能试验研究

摘要

To investigate blast-resistant capacities of RPC filled steel tubular columns (RPC-FSTCs)after exposure to fire,time history curves of reflected overpressure of blast load and displacements and strains of specimens were obtained with field explosion tests of 4 large scale RPC-FSTC specimens.The influences of fire duration time and scale distance of charge on behaviors of RPC-FSTCs were also analyzed.It was shown that the RPC-FSTCs keep an excellent blast-resistant capacity after exposure to fire;RPC core column can be effectively constrained by steel tube under explosion load after the RPC-FSTCs are exposed to fire;the blast-resistant capacity of RPC-FSTCs decreases with increase in fire duration time;the RPC-FSTCs without fire exposure keep elastic state with a scale distance of 0.58 m /kg1 /3 .RPC-FSTCs with fire duration time of 60 min keep better deformable and shear resistance capabilities,but the flexure failure of specimens tends to the flexure-shear failure when the scale distance of 0.58 m /kg1 /3 decreases to the scale distance of 0.48 m /kg1 /3;the deformable capacity of RPC-FSTCs with the fire duration time of 105 min decreases greatly,obvious plastic hinge are observed at the mid-span of RPC-FSTCs with the scale distance of 0.58 m /kg1 /3;the maximum displacement and residual displacement of the mid-span increase by 0.4 times and 1.6 times,respectively compared with those of RPC-FSTCs with the fire duration time of 60 min;so,the fire duration time has a great influence on the blast-resistant capacity of RPC filled steel tubular columns after exposure to fire.%为研究钢管活性粉末混凝土（钢管RPC）柱火灾后的抗爆性能。通过4根大比例钢管RPC柱试件的野外抗爆试验，得到了冲击波反射压力和钢管 RPC 柱的位移、应变时程曲线，分析了不同受火时间和比例距离对火灾后钢管RPC 柱抗爆性能的影响。结果表明：钢管 RPC 柱具有良好的抗爆性能，受火后的钢管 RPC 柱在爆炸荷载作用下钢管仍能有效约束 RPC，但随着受火时间的增加钢管 RPC 柱的抗爆能力减弱。未受火的钢管 RPC 柱在比例距离为0．58 m／kg1／3的爆炸荷载作用下基本处于弹性状态；受火60 min 的钢管 RPC 柱仍具有较好的变形性能和抗剪能力，但当比例距离由0．58 m／kg1／3减小到0．48 m／kg1／3时，试件出现由弯曲破坏过渡到弯剪破坏的趋势；受火105 min 的钢管 RPC 柱变形性能显著下降，在比例距离为0．58 m／kg1／3的爆炸荷载作用下跨中处出现明显的塑性铰，跨中最大位移和残余位移分别比受火60 min 的工况增加0．4倍和1．6倍，说明受火时间对火灾后钢管 RPC 柱的抗爆性能有较大影响。