Fatigue cracking simulation of aged asphalt pavements using a viscoelastic continuum damage model

Few information in the literature indicates how aging affects the service life of asphalt pavements. This work presents linear viscoelasticity and damage characterisation of an asphalt mixture at four aging states, and simulation of pavements fatigue performance. E* tests were performed in sinusoidal compression. Controlled crosshead tension-compression testing was used for damage characterisation. Aged materials were obtained by heating loose asphalt mixture at two temperatures (85 degrees C and 135 degrees C) and aging times (2 and 45 days). Two simulated pavements were studied for comparing behaviour at different ages using Layered Viscoelastic Pavement Analysis for Critical Distresses (LVECD). Results showed that the effect of aging seems to improve service life. It was also observed that simulating the asphalt layer as composed by two half-layers (aged at the top and unaged at the bottom) did not lead to significantly different results with respect to fatigue performance of an evenly aged layer.