REINFORCED CONCRETE SLABS
Slabs are plate elements forming floors and roofs in buildings, which normally carry uniformly, distributed loads acting normal to the plane of the slab. In general at a slab section, bending moments in two orthogonal directions and twisting moments are present. Slabs may be simply supported or continuous over one or more supports and are classified according to the method of support as follows:
1. spanning one way between beams or walls 2. spanning two ways between the support beams or walls 3. flat slabs carried on columns and edge beams or walls with no interior beams
Slabs may be solid of uniform thickness or ribbed with ribs running in one or two directions. Slabs with varying depth are generally not used. Stairs with various support conditions form a special case of sloping slabs.