冲击受损RC梁残余力学性能试验-《建筑科学与工程学报》

文章信息/Info

Title:: Experiment on Residual Mechanical Behavior of Impact-damaged RC Beams

Author(s):: LI Zhi, HU Kai-ying, HUO Jing-si, ZENG Xiang; Key Laboratory of Building Safety and Energy Efficiency of Ministry of Education, Hunan University

Keywords:: RC beam; impacted damage; residual resistance; residual stiffness; residual deformation capacity

摘要:: 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。

Abstract:: In order to provide the basis for repairing, strengthening and structural safety assessment of impact-damaged reinforced concrete (RC) beams,static load tests on 3 RC beams impact-damaged by drop hammer and contrast test on static load beam were carried out.The RC beams suffered different degrees of impact damage by changing impact energy, and the residual mechanical behaviors of impact-damaged RC beams were studied. The crack development patterns of beams under different impact energies, and change laws of impact load, reaction force, mid-span deflection and reinforcement strain in mid-span were compared and analyzed. The residual capacity, residual stiffness and residual deformation resistance of beams were investigated with different impact damages. Moreover, on the basis of integrated analysis of the related literature and normalized impact energy, the calculating formulas of residual resistance and residual stiffness were fitted out.The test results show that with the increase of impact energy, deflection-span ratio enhances, but the residual resistance and stiffness decrease generally. Compared with the undamaged beam, the residual capacity and residual stiffness increase before declining, the ductility evidently decreases at the latter stage.