Buildings may experience impact loads or even multiple impacts during their service life. Precast concrete (PC) structures have been widely used in engineering, with PC beams serving as the primary load-bearing components in these structures. In this study, six PC beams and two cast-in-place reinforced concrete (RC) beams were designed and manufactured, and drop hammer impact tests were conducted. Additionally, static load tests were conducted on two corresponding PC and RC beams. The experimental study provided benchmark data examining the influence of varying drop hammer mass, impact velocity, and level of pre-damage on the dynamic response of the PC beams, including their failure mode, mid-span deflection, impact force, deflection recovery ratio, and deformation energy consumption. The experimental results confirmed the reliability of using pressure sleeve connection as the assembly and connection form of PC beams. Under equivalent energy conditions, an increase in impact mass simultaneously leads to a decrease in peak and residual deflection of PC beams. This reduction is accompanied by an increase in their average impact force. Under the same impact mass and velocity conditions, the peak deflection of beams exhibiting different degrees of damage exceeded that of undamaged beams, although their residual deflection was relatively lower. In addition, the deflection recovery rate of damaged beams is slightly higher than that of undamaged beams.
Read full abstract