This study investigated the effect crumb rubber recycled from wasted tires on properties of structural lightweight aggregate concrete (LWAC). Two types were tested: control LWAC and rubberized (RLWAC). The consisted cement, fine (river sand), coarse (porous aggregates). For RLWAC, was replaced by at rate 10, 20, 30, 40, 50% volume. water to cement ratio for both set 0.35. experiment series dens...