| In recent years, various explosion and impact events occur with hunman’s comcunications enhancing so that engineering structures are seriously damaged by these extreme loadings. Nevertheless, except the firsthand damage to the structure, explosion and impact may also trigger fire which has detrimental effects on structures. Now, lots of reserches to the anti-impact performance of the reinforcement concrete(RC) beams have been conducted and the fire performance of undamaged elements under high temperature was continually investigated at home and abroad but the fire performance of impactive damaged RC beams was rarely investigated. Therefore, in this paper drop test machine was used to study the dynamic response of the RC beams under impact loadings and the fire performance of these beams was investigated, which can provide references for the structure anti-impact and anti-collapse design. The main jobs have been done as follows:(1) Drop impact tests on RC beams were carried out. The cracks ’ failure mode and the histories of the impact loading, support reaction force, mid-span deflection and reinforcement strain in mid-span were investigated as well as the inertia force and acceleration of the beam were analyzed.(2) The failure mechanism of the beams was investigated under impact loadings and numerical simulations about the dynamic response were developed with LS-DYNA. The applicability of empirical formula to estimate residual deflection under impact loadings and were discussed. Based on the collection and analysis of the impact test results in related papers, the applicability of empirical formula to estimate residual deflection under impact loadings was discussed. Tests of residual capcities of some beams damaged by impact loadings were carried out and the residual bearing capacities were analyzed.(3) Fire performance tests on impactive damaged RC beams were carried out. The influence of impactive damage levels and loading ratio on the fire resitence was discussed especially. |
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