MECHANISTIC EVALUATION OF FLY-ASH ASPHALT CONCRETE MIXTURES

This investigation was carried out: (1) to study the effect of fly ash on the mechanical properties of asphalt mixtures; and (2) to evaluate the effect of using fly ash in mitigating pavement distress and impro ving performance of asphalt concrete pavement. In this study, four gro ups of specimens with various fly ash contents were studied. The mecha nical properties (resilient modulus, creep, permanent deformation, and fatigue) were determined at three different temperatures. Moisture da mage tests were carried out. The VESYS model was used to predict pavem ent performance. Results from this study indicated that fly ash can be used as a mineral filler to improve resilient modulus characteristics and stripping resistance. The addition of fly ash did not significant ly reduce field performance of asphalt concrete mix in terms of rut de pth and present serviceability index but increase the amount of surfac e cracking in the pavement.