Experimental and numerical research on reinforced concrete slabs strengthened with POZD coated corrugated steel under contact explosive load

In recent years, with the rising of terrorism around the world, new materials and new protection technologies have developed rapidly. In this article, the anti-blast performance of reinforced concrete (RC) slabs strengthened with polyisocyanate oxazolidine (POZD) coated corrugated steel has been studied through contact blast tests and numerical simulations. Two specimens were fabricated, including RC slabs strengthened with corrugated steel and RC slabs strengthened with POZD coated corrugated steel. The failure characteristics of the structure were analyzed. The damage mechanism was revealed by the transmission of stress waves. Additionally, the finite element model of the specimens was established by the Arbitrary-Lagrangian-Eulerian method. The damage modes of the structure under different TNT charges were studied. Then the empirical expressions between failure characteristics (maximum mid-span displacement, bulge long diameter, bulge short diameter) and TNT charges were fitted by dimensionless analysis. The influence of POZD on the anti-blast performance of the structure was studied from three perspectives (maximum mid-span displacement, stress wave attenuation rate, and internal energy absorption). The results demonstrated that with the increase of TNT, the failure characteristics of the structure showed an approximate linear growth trend. When the ratio of the thickness of corrugated steel to the thickness of POZD was 3:2, the explosion resistance was the best.