A two-way slab is a type of concrete slab system in which two rebars are arranged in two directions, regardless of the presence or absence of a beam that transmits a load to a column. In ACI 318, this is expressed as ‘slab systems reinforce flexure in more than one direction, with or without beams between supports’ . Two-way slabs are generally supported on all sides by walls or beams, and the loads are carried by the supports along both directions. The ratio of longer span to shorter span is less than two, and the slab twists or bends in both directions while transferring the loads to the walls or beams. The main reinforcement is provided in both directions for two-way slabs. Typical types of two-way slab systems commonly used today include two-way slabs with beams, flat plates, flat slabs, and waffle slabs.