Penetration resistance and damage characteristics of cementitious mortar with partially replaced waste tire rubber as a filler against high-speed impact loading

Abstract

Concrete, as the sole construction material, demonstrates an inadequate performance against high-speed impact loading. Resistance to such loading can be increased by adding rubber from the waste tire industry. In this study, the performances of cementitious mortar with the addition of waste tire rubber (WTR) powder were investigated against the strike of a high-speed projectile. By setting the target flow above 110 % and air content within a range of 5–7%, mortar with 30 % WTR was selected for high-speed impact test. Selected mortar specimens demonstrated significantly high resistance to damage and penetration against a high-speed projectile at impact speeds of 300 m/s and 420 m/s. Further, an experimental study revealed the contrasting behaviour of mortar specimens with WTR powder from that of conventional specimens, where typical compression occurred due to triaxial stress at the tunnel circumference formed by the intrusion of the projectile. Recommendation is made for composite mortar containing a less-stiff material such as rubber for new variables to be defined in the existing formulae, to quantify penetration in high-speed loading; given that the penetration resistance of specimens with 30 % WTR was larger than that of the control specimen, even with its lower compression strength.