Penetration resistance of concrete reinforced by hybrid fibre subjected to multiple projectile impacts

Penetration resistance of steel-ultrahigh molecular weight polyethylene (S-UHMWPE) hybrid-fibre-reinforced concrete under multiple projectile impacts are investigated. In this paper, 16 sets of hybrids with various hybridizations were designed and prepared considering 0%-1.5% steel fibre volume and 0%-0.3% UHMWPE fibre volume. Each hybrid-fibre concrete target was stroke triple times sequentially under 12.7mm armor-piercing projectile. The projectile impact locations are among the middle of the target in equilateral triangle shape. After each penetration, depth of penetration (DOP) and crater area were investigated. Results show that hybrid-fibre concrete performs much better than steel or UHMWPE fibre reinforced concrete with less crater area and lower DOP for hybrid-fibre concrete combines the reinforcement and toughening effect of UHMWPE fibre on concrete's tensile strength and strengthening effect of steel fibre on concrete's compressive strength. Besides, the crater area caused by each impact decreased with the number of strikes increases.