EFFECT OF COMPOSITE INTERACTION ON MOMENT OF RESISTANCE: ANALYTICAL STUDIES ON COMPOSITE SLAB

Since the inception of a composite slab, many aspects of the composite structural interaction between steel deck and concrete have been studied and reported in different parts of the world. Researchers Luttrell and Prasannan (1984), stated that composite slab with profile deck behaves differently than R.C.C. slabs and therefore, the geometry of the deck has a great effect on the resistance. They developed equations for the moment capacity based on relaxation factors. Jolly and Zubair (1987) mentioned in their research that, effective composite action is achieved by increasing the depths of protrusions. Depth is the most prominent factor but higher protrusion depths may lead to tearing of steel deck during production. Heagler (1992) discovered the moment equation based on transformed area. In his studies he considered separate tensile forces of profile sheet as of the top and bottom flanges and the web separately with their respective moment arms. Effect of profile protrusion is not considered in Heagler's method. Wright and Veljkovic (1996) have modeled composite slab by finite element analysis and they mentioned important observations regarding the mechanism of failure. Roger (2006), argued that the design data provided by profile deck manufacturers are based on tests which may not be in accordance with standards of the country. Verification of the profile sheet is mandatory before its use in construction.