Dynamic response of monolithic and precast concrete joint with wet connections under impact loads

Precast concrete (PC) structures have been popularly used in construction practice and PC beam-column joints are critical for structural integrity and safety. In this study, dynamic responses of one monolithic reinforced concrete (RC) joint and three PC joints with different wet connection configurations were investigated by using a pendulum impact test system. The impact behaviours of monolithic RC and PC joints were examined and compared in terms of failure modes, dynamic responses, and energy dissipation. The effects of various wet connection configurations on the dynamic response of PC joints were discussed and analysed. It is found that the interface damage between PC beam and joint led to the reduced integrity of the PC joints. In addition, numerical models of beam-column joints were developed by using software LS-DYNA and calibrated by the test data. The calibrated numerical model was used to investigate the influences of various wet joint configurations on its performance subjected to impact at different locations. Numerical results showed that the shear key and interface rebar employed for wet connections were beneficial to resist shear-governed damage but less effective in resisting flexural-governed damage induced by impact loads. Therefore, the wet connections should be properly designed for PC joint to resist the designated impact loading scenarios.