Rutting parameters for asphalt concrete for different aggregate structures

Pavements are subjected to many distresses during their service lives. One of the main distresses that a pavement is subjected to is rutting. This paper focuses on the effect of using a fine or coarse gradation, as related to the restricted zone, on the rutting behaviour of asphalt concrete in flexible pavements. The restricted zone was one of the Superpave gradation selection criteria. This was done through traffic-simulated dynamic testing programme of asphalt concrete made of Egyptian materials. The Ohio state model as one of the models that could be used in predicting rutting was employed in this research. The model relates rutting to the resilient and residual properties of the pavement. The experimental results were analysed according to that model. It was found that fine gradations, passing above the restricted zone, were more susceptible to rutting especially for higher deviator stress.