Foundations: the concrete block or poured concrete walls of basement or sublevel. Cement: dry mixture of lime, silica, alumina, and other materials used to bring nonadhesive materials together into a strong, cohesive unit. Concrete:the building material made by mixing cement and a mineral aggregate (gravel) with sufficient water to cause the cement to set into a hard mass. Reinforced concrete: has rebar (strong, bendable steel bars) or wire mesh set into the wet mixture before it is dried to give structural strength and prevent cracking. Flatwork: cement for basement floors, garage floors, driveways, and walkways; it may be reinforced and poured over sand, gravel, wire mesh or rebar to minimize shifting and settling that produce cracks.