EVALUATION OF POLYMER-MODIFIED ASPHALT CONCRETE MIXTURES

Since the mid-1980s, polymer-modified asphalt concrete mixtures have been widely used to minimize rutting failures of flexible pavements. This research investigates the permanent deformation behavior of unmodified asphalt concrete mixtures as compared to the behavior of asphalt concrete mixtures modified with polyethylene. The rutting resistances of the mixtures at 40 degrees C and 60 degrees C are evaluated in the laboratory using the repeated-load permanent-deformation test. The data from the repeated-load permanent-deformation tests are used in the VESYS model to predict the rutting development of typical pavement structures built with both modified and unmodified mixtures. The analysis of the VESYS results indicate that the polyethylene-modified mixtures exhibit higher resistance to rutting than the unmodified ones. In addition, the layer coefficients of the polyethylene-modified mixtures were 75-85% higher than the layer coefficients of the unmodified ones.