Enhancement of the Rutting Resistance of Asphalt Mixtures Modified by Nano Clay and Crumb Rubber

In recent years the increased traffic, axle load, tire pressure, and hot weather have hastened the spread of rutting in flexible pavements. Recent research indicates that nanomaterials and crumb rubber considerably alter asphaltic mixture characteristics. This research aims to examine the impact of Nano Clay (NC) combined with Crumb Rubber (CR) on the Marshall characteristics and the rutting resistance of HMA. It involves determining the optimal asphalt content, by using the method of Marshall design, as well as the rutting depth for asphalt mixes with varying amounts of NC (1%, 3%, and 5%) and CR (10%, 20%, and 30%) as a percentage of the asphalt binder. The optimal content of asphalt was 4.93% for the control mix. The Marshall stability was enhanced by the inclusion of NC and CR, with the combination of 5% NC and 30% CR exhibiting the most significant increase of 20.9%. Marshall flow was decreased by adding NC and CR. The control mix had a Marshall flow of 3.30 mm, but when using 3% of NC and 30% of CR, the flow decreased to 2.88 mm, which was the greatest reduction. The ideal proportion of NC and CR was 5% and 30%, respectively. This resulted in a 40.85% reduction in rut depth compared to the control mixture.