Experimental analysis of longitudinal shear of composite slabs

The composite concrete slab systems with steel-deck incorporated has become an alternative to conventional slab models, since it often does not require the use of shoring, promoting several constructive practices, beyond operation of the reinforcement as a positive moment. The procedure of verification of composite slabs is based on the semi-empirical method m and k. The purpose of this paper was to investigate the application of the "m-k method" in a group of slabs with alternative dimensions as the usually adopted in the tests, even as to correlate the values obtained with the results found when testing the models as proposed by the ANSI 2011 test standard, since the normative method is costly and expensive. Therefore, four-point flexural tests were performed on slab models considering only one deck module, varying two spans, the same procedure was repeated in slabs with usual construction dimensions (normative models). The linear regression method was applied to the data found in order to obtain the parameters that would be analyzed. The main results show that the alternative model with the adopted dimensions does not present values that can be applied directly to the normative models, since the increase of the shear span reduces in a significant way the theoretical resistance of the slabs. Nevertheless, the values for the m and k obtained of both alternative and normative models can be adopted confidently as part of the sizing process of the respective models. The deviations between theoretical and experimental resistance satisfy the specifications of the ANSI 2011 standard for both models helped in the confirmation of the previous statement. The expectation of this paper is to assist in the search for new procedures for determining parameters m and k.