Near-field multiple-blast resistance of G‑HPC sandwich walls incorporated with metallic tube core

Multiple-blast loading induced in one explosion case more significantly threatens the safety of engineering structures, compared with single-blast loading. This study first proposed a novel sandwich wall based on the steel wire mesh (SWM) geopolymer based high-performance concrete (G-HPC) slab and metallic tube core (MTC) to mitigate the threat induced by the multiple-blast loading. The dynamic responses and failure mechanism of the sandwich wall was investigated by field blast tests and numerical simulations. The damage to the sandwich wall under different multiple-blast scenes was estimated in detail. The effect of parameters including the spacing of the steel tubes and the thickness of the front/rear slab was also investigated by numerical simulations. The experimental results showed that the sandwich walls could still maintain the integrity, indicating an excellent multiple-blast resistance. The numerical results illustrated that the front slabs could directly resist the multiple-blast loading and the metallic tube core could further mitigate the blast wave propagation. The parametric analysis indicated that the increase in the thickness of the rear slab improves the multiple-blast resistance of the sandwich wall.