slab definition
A slab is a large, flat, thick piece of raw material, usually a few inches thick. Sidewalks are usually made from concrete slabs. Horizontal slabs of steel reinforced concrete, usually between 100 and 500mm thick, are used to build floors and ceilings. A slab is a large, flat, thick piece of raw material, usually a few inches thick. Sidewalks are usually made from concrete slabs.Horizontal slabs of steel reinforced concrete, usually between 100 and 500mm thick, are used to build floors and ceilings.