Effects of geometry on the deformation of asphaltic plug joints subjected to surface tractions

Asphaltic plug joints are widely used for accommodating structural movement in motorway bridges. In spite of their simplicity and low cost, these joints suffer premature failure, of which debonding at the asphaltic plug/pavement interface is an important mode. In this paper, fundamental studies of the debonding are carried out by means of detailed stress analysis. The asphaltic plug is assumed to be viscoelastic while the pavement is assumed to be linear elastic. Stress solutions are obtained using the finite element method for a range of joint angles between the asphaltic plug and the pavement. The traffic loads are simulated using surface tractions applied in the vicinity of an interface corner on the wearing surface. The results show that the interface may experience stress reversal as the surface traction moves from one side of the interface corner to the other. Further, the magnitudes of the interfacial stresses decrease as the joint angle is increased from the current value of 0° to about 45°, thereby reducing the likelihood of debonding.