Prediction of the debonding/ slip load of composite deck slabs using fracture mechanics

The aim of this paper is to develop equations that can be used to predict the load at which debonding or slip occurs in composite deck slabs, failing as a result of shear bond rupture. Debonding is the separation of the bonded steel plate from the concrete. The expressions are based on end-slip of the shear span occurring prior to ultimate load. Shear bond failure is considered to be a result of breakdown of mechanical and frictional resistance force between the steel and the concrete interface. Linear elastic fracture mechanics (LEFM) is assumed and the eccentric axial force transmitted by the steel deck is calculated using rotational congruence. The theoretical debonding load results are found to be comparable with experimental results, and to be of use in formulating the response of composite slabs when subjected to fatigue load.