Blast resistance of air-backed RC slab against underwater contact explosion

Abstract

Reinforced concrete (RC) structures are common in engineering, and usually exposed to air or water, may be subjected to various blast scenarios. This paper aims to investigate the blast resistance of an air-backed RC slab against underwater contact explosions (UWCEs). A detailed numerical model based on CLE method considering explosive, water, air, and RC slab is developed to examine the structural behavior of the air-backed RC slab due to UWCEs. At first, the reliability of the numerical method is validated by comparing the numerical results of an UWCE test with experimental data. Then, the difference in dynamic behavior of air-backed and water-backed RC slabs due to UWCEs is explored with the calibrated model. The results indicate that the blast response of the air-backed slab induced by UWCE is fiercer than that of water-backed slab with equal charge mass. In addition, parametric studies are also conducted to explore the effects of the charge mass, standoff distance, reinforcement spacing, concrete compression strength, and boundary condition on the blast performance of the air-backed RC slab.