Experimental studies and numerical simulation of behavior of RC beams retrofitted with HSSWM-HPM under impact loading

High Strength Steel Wire Mesh and High Performance Mortar (HSSWM-HPM) are widely used for structural reinforcement and retrofit. Recent research suggests that HSSWM-HPM can be applied to enhance seismic loading-resistance of structures. In this study, the mechanical performance of reinforced concrete (RC) beams covered with the HSSWM-HPM under impact loading were evaluated using both laboratory experiments, and numerical simulations. In the laboratory experiments, the performance of eight full-size beams, including five retrofitted RC beams and three un-retrofitted RC beams, subjected to the drop-weight impact loading and static loading were evaluated. During the drop-weight impact tests, the contributions of the following critical parameters, including the impact loads, strains, accelerations, velocities, and deflections of the beams, and residual damage, were studied and compared among different specimens. Another comparative study on the failure pattern and the impact resistance of beams with and without reinforcement were performed in the commercial finite element software LS-DYNA. A general prediction of response time histories and maximum mid-span deflections of the beams were obtained from LS-DYNA. The results obtained from both laboratory experiments and finite element analyses indicated that the impact resistance and ductility of the RC beams were significantly improved after retrofitted with HSSWM-HPM.