Experimental investigation on shear-bond mechanism and strength of composite slabs with steel profiles

In most cases, strength of composite slabs is governed by shear-bond failure at the sheeting-concrete interface. Considerable improvement of longitudinal shear-bond load carrying characteristic is acquired for composite slabs with end anchorage. However, current design procedures to assess the shear-bond strength, such as the m-k method and the partial connection method (τu), are not considerate for the influence of end anchorage. Thirteen full scale simply supported composite slabs were tested by varying the influence parameters like span length, slab depth, shear span length and the end anchorages which was provided by the steel headed studs. Based on an analysis of deflection, end slip and the distribution of strain of the cross section, the shear-bond failure mechanism of composite slabs is revealed. In terms of the internal force and deformation relationship, the sheeting-concrete interface longitudinal shear force is revealed in the term of vertical shear force. The test results were appraised using present design procedures. Based on the ultimate shear-bond state, a simplified method is proposed for τu method. The method has been validated and the results predicted by the simplified method agree well with the test results.