Abstract: Rubber-crumb-reinforced cement-concrete structures (such as mortar (0), cement board (30), concrete masonry units (40), and concrete pipe (50)) provide resistance to cracking, increase resistance to acid rain, lower weight, improve shock wave absorption, lower heat conductivity and improve the acoustical environment. The structures preferably are made of concrete having a predetermined proportion (from about 1 to about 30 parts by weight per 100 parts by weight of cement) of recycled scrap rubber crumbs which are preferably undirectionally aligned in the cross-section of the structures.

Abstract: Rubber crumb reinforced cement-concrete structures provide resistance to cracking, improve shock wave absorption, lower heat conductivity and improve the acoustical environment. The structures are comprised of cement-like materials having a predetermined proportion (from about 1% to about 30% by weight of cement) of recycled scrap rubber crumbs undirectionally aligned in the cross section of said structures.