Experimental and Numerical Investigation of Steel-Concrete Composite Waffle Slab Behavior

This paper proposes a new kind of composite waffle slab that consists of orthogonal steel girders and flat RC slab. The steel beams help decrease the cracking that occurs with concrete, and using prefabricated RC slabs reduces the framework and speeds up the construction. An experimental investigation of steel-concrete composite waffle slabs is conducted, and the specimens are proved to have excellent ductility and load-bearing capacity. Then a mixed finite-element (FE) model combining the beam elements and shell elements is proposed to predict the behavior of composite waffle slab. Based on the numerical model, a series of parameter analyses are conducted, and the influences of different parameters on the mechanical behavior of the composite waffle slab are intensively investigated. Simplified formulas for the ultimate capacity of the composite waffle slab are derived based on the test observations and numerical analysis. Reasonable recommendations are proposed to help engineers design the composite waffle slab effectively. (C) 2015 American Society of Civil Engineers.