ABSTRACT

Any crack or joint in a pavement tends to reflect through an overlay placed on the cracked pavement (see figure 2.1). The rate at which the reflection process develops depends on the magnitude of the stress concentrations at the tip of the crack or joint, the resistance of the overlay material to crack propagation and the characteristics of the interface between the overlay and the existing pavement. The stress concentrations at the tip of a crack or joint develop as a result of the bending, shearing and tearing actions of traffic loads and tensile and bending actions caused by temperature and moisture movements as well as temperature and moisture gradients.