This paper outlines a procedure for the design of asphaltic concrete overlays on existing asphalt concrete and portland cement concrete pavement surfaces. It discusses the type and form of information required by the microcomputer-based design program and all elements necessary for the user to design an overlay. The program provides an estimate of the time and number of traffic loads to failure by reflective cracking. The design equations are based on fracture mechanics and represent the existing pavement as a beam on an elastic foundation. The equations address fracture in the slab due to bending and shear caused by moving wheel loads and due to opening caused by thermal movement of the cracked existing pavements.
Abstract