Abstract

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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

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.