ABSTRACT
The objective of this research is to enhance the 1993 AASHTO design methodology for asphalt pavements by integrating the dynamic modulus of asphalt mixtures in the design process. The aim is to provide a more accurate estimate of the structural coefficient ‘a’ of the asphalt layer (i), representative of the prevalent climatic and traffic conditions, by establishing a new relationship between the structural coefficient and the effective dynamic modulus (|E*|eff.) of the asphalt mix. The research resulted in the development of a multivariate relationship between the structural layer coefficient ‘a’, the effective dynamic modulus of the asphalt mix (|E*|eff.), and the resilient modulus of the aggregate base layer (Ebase). A Microsoft-Excel-based pavement structural design tool was subsequently built to support the developed ai –|E*|eff.–Ebase relationship, and simplify calculations. Design thicknesses acquired using the tool are generally close to those acquired using AASHTO’s Mechanistic-Empirical Guide through the Pavement-ME software.
