Experimental study of bulletproof concrete

This paper focuses on the study of composite concrete specimen’s resistance under an impact of AK-47 bullet with an estimated projectile’s speed of 715 m/s, and energy of 2019 J. Two sets of samples (a total of nine samples) are fabricated and tested from mortar with 1 cm steel fibers or 1 cm carbon fibers respectively. Tensile and compression tests are applied for the first set of samples, to investigate the effect of steel and carbon fibers on the strength of the specimens. Two ratios (1% and 2%) of fibers per mortar mass are also experienced before assessing the bullet resistance. For the second set of samples, three different composite sandwich configurations are tested with a rear impact test. An Armox-® 500 T plate is applied in front of mortar panels for two configurations. Results show that the addition of carbon and steel fibers to concrete panels enhances the impact resistance of concrete by keeping the panels coherent and preventing them from breaking into fragments, reducing crater diameters and detached mass. The three proposed configurations of sandwiches panels stopped the full perforation of the bullet.