Influence of rubber powder size and volume fraction on dynamic compressive properties of rubberized mortar

Rubber particles taken from waste tires have been proposed as a prospective substitute for natural aggregates. Although the dynamic mechanical responses of rubberized concrete have been studied considerably, rubberized mortar without coarse aggregates is desired for laboratory constitutive study due to the uniformity requirement. This work uses rubber particles with sizes of 40, 80, and 120 mesh and volume percentages of 10%, 20%, 30%, and 40% to prepare mortar specimens. A split Hopkinson pressure bar combined with a momentum-trap device is utilized to apply dynamic loads. Experimental results indicate that the dynamic compressive strength of rubberized mortar increases with rubber sizes but is negatively correlated to volume fraction. The reduction in the dynamic strength of rubberized mortar is less evident as compared to that of rubberized concrete investigated in previous studies. Additionally, the incorporation of rubber powder with smaller size can slightly improve the energy absorption capacity of rubberized mortar.