Effect of reclaimed asphalt pavement in granular base layers on predicted pavement performance in Egypt

This research presents the prediction of pavement performance constructed with base layer consisting of reclaimed asphalt pavement (RAP)/virgin aggregate blends. The prediction was made by the Multi-Layer Elastic Analysis software (KENLAYER) in terms of horizontal tensile strain at the bottom of AC layer and the vertical resilient strain at critical locations within the pavement system. The dynamic modulus |E*| for the hot mix asphalt was estimated by using the quality-related specifications software considering three different climatic conditions and two levels of design speeds. Finally, total pavement rutting and fatigue cracking were determined using the critical strains computed by the Multi-Layer Elastic Analysis along with the Mechanistic Empirical Pavement Design Guide performance models and transfer functions. In general, the RAP blends showed superior/comparable performance compared to natural aggregates for the application in base/subbase layers for the Egyptian conditions. The effect of the rate of loading and climate conditions was significant on both asphalt concrete layer fatigue cracking and rutting.