Segregation of asphalt mixtures, which denotes the non-uniform distribution of coarse and fineaggregate components, either causes short term premature failures or affects the long termpavement performance. Since segregation may result in a significantly altered aggregatestructure of an asphalt mixture, it may increase the potential for rutting, among all otherdistresses. In this study, the effect of segregation or change in aggregate gradation that maynegatively influence the rutting potential of asphalt mixtures was evaluated. The DominantAggregate Size Range (DASR) gradation model and the DASR porosity parameter, which havepreviously been identified to be well correlated with rutting performance, were used to identifythe potential degradation of rutting performance due to segregation. A total of four roadwaysections with different severity levels of segregation were selected and evaluated. The analysisresults of mixture gradation, volumetric properties, and DASR porosity indicated that segregatedmixtures exhibited a significant shift in gradation, especially for the coarse aggregate portion ofthe mixture gradation. Consequently, it was found that segregation of asphalt mixtures maysignificantly increase the potential for rutting. However, a need still exists for future verificationusing the actual field or laboratory rutting performance data, which were not available in thisstudy.
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