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为给冲击受损后钢筋混凝土(RC)梁的修复加固和结构安全评估提供参考,开展了3根RC梁落锤冲击受损后的静载试验及1根静载梁的对比试验,通过变化冲击能量使RC梁遭受不同程度的冲击损伤,对冲击受损后RC梁的残余力学性能进行研究。比较分析了不同冲击能量下受损梁的裂缝发展形态以及冲击力、支座反力、跨中挠度和纵筋应变变化规律;重点研究了不同受损程度梁的残余承载力、残余抗弯刚度和残余变形能力。在综合分析相关文献试验数据并对冲击能量进行标准化的基础上,拟合出冲击受损后RC梁残余承载力与残余抗弯刚度的计算公式。结果表明:随着冲击能量增大,冲击损伤梁挠跨比也增大,残余承载力和刚度总体呈下降趋势;相比未损伤梁,冲击损伤梁弹性抗弯刚度和极限抗弯承载力先增大后减小,但加载后期延性明显降低。
In order to provide reference for the reinforcement and structural safety assessment of reinforced concrete (RC) beams after impact damage, the static load test and the comparative test of one static load beam with three RC beams subjected to impact damage were carried out. The impact energy causes the RC beam to suffer different degrees of impact damage, and the residual mechanical properties of the RC beam after the impacted impact are studied. The development pattern of the crack, the reaction force of the abutment, the mid-span deflection and the longitudinal reinforcement strain of the damaged beam under different impact energies were comparatively analyzed. The residual bearing capacity, residual flexural rigidity And residual deformation capacity. Based on the comprehensive analysis of the related experimental data and the standardization of the impact energy, the formula for calculating the residual bearing capacity and residual bending stiffness of RC beams after impact damage is obtained. The results show that with the increase of impact energy, the ratio of the flexural and span-span of impact damage beam also increases, and the residual bearing capacity and stiffness generally decrease. Compared with the un-damaged beam, the flexural rigidity and the ultimate flexural capacity of the beam Increased after the decrease, but the load late ductility significantly reduced.