Mesoscale simulations of the impact resistance performance of rein-forced concrete beams exposed to high temperature

Abstract

Considering the degradation of the mechanical properties of steel and concrete under high temperature and the strain rate effect of the materials, a mesoscopic numerical analysis model of reinforced concrete beam are proposed based on the meso-structure of concrete. The influences of fire duration time and impact energy on the impact resistance behavior of concrete beams in fire are discussed. In this paper, the failure process of reinforced concrete beam subjected to impact load, the impact force time history, the reaction time of support and the displacement response in the middle span are analyzed. The results show that the mesoscopic numerical model can well simulate the heat transfer process of each components of concrete. With the increase of heating time, the concrete beam under the impact load is more serious, meanwhile the duration of the impact force and the maximum displacement of the span increase, but the impact force peak decreases; with the increase of impact energy, the shear failure of concrete beam is more serious, and the impact force peak increases. The maximum displacement increases linearly with the impact energy.