Improving the Impact Resistance and Antisplash of Civil Air Defense Wall: Experiments and Finite-Element Simulation

In order to avoid the occurrence of serious casualties and secondary injuries caused by high-speed splashing concrete fragments, pendulum impact test research and numerical analysis were carried out for the first time on the civil air defense wall sprayed with 2-mm polyisocyanate-oxazodone (POZD) coatings at different positions. The results showed that spraying a 2-mm POZD coating on the civil air defense wall can significantly reduce the damage area of the wall, restrain the splashing of concrete fragments, ensure the integrity of the wall, and improve the impact resistance and airtightness of the civil air defense wall. The large-rupture-strain fiber-reinforced polymer (FRP) pasted on the back significantly improved the bending stiffness and deformation capacity and reduced the residual displacement of the wall. The failure modes and failure characteristics of the wall obtained through the experiments in this paper provide the failure evaluation criteria for existing civil air defense walls.