Performance of Grouting Sleeve-Connected Prefabricated Beams Subjected to Impact Loading

The potential of accidental loads such as explosions and impacts cannot be overlooked given the widespread use of precast concrete (PC) buildings. However, research on the impact resistance of reinforced concrete precast beams is limited. In order to explore the dynamic behavior of PC beams connected by grouted sleeves under impact loads, this work developed a numerical model based on the finite element program LS-DYNA. First, the experimental process was described in detail, and the numerical model was evaluated and calibrated according to the experimental data. Then, parameters such as impact location, concrete strength of precast section and stirrup rate of cast-in-place area were studied. Finally, a simpler model based on equal high-frequency impulse impact force was suggested, and the viability of a single-degree-of-freedom model theory was proved for the dynamic analysis of PC simply supported beams subjected to impact loading. According to the findings, the interface of precast concrete and cast-in-place concrete is the weak point of the PC beam, which is prone to shear damage under impact loads. Second, when the middle of the cast-in-place part of the PC beam is impacted, wide cracks from the bottom to the top are quite likely to form. As a result, the most disadvantageous impact position for PC beams is in the middle of the cast-in-place portion. Although increasing the concrete strength of the precast section can reduce crack formation, it has minimal influence on the interface’s shear resistance. Furthermore, increasing the stirrup rate in the post-cast portion can increase the overall shear resistance of the PC beams.