Assessment of Asphalt Mixture Performance Subjected to Production and Paving Segregation

In this study, the effect of aggregate segregation on the performance of hot mix asphalt was studied. The possible levels of aggregate segregation were arrived from the field core samples. Considering the level of segregation observed in the field, four levels of segregation that range from very fine to very coarse were simulated in the laboratory. Both production and paving segregation were simulated to explore the effect on asphalt mixture performance. Production segregation was imitated by sieving aggregates through 2.36 mm and batching in different proportions. Alternatively, a loose hot asphalt mixture was sieved on a 4.75-mm sieve and combined in different proportions to mimic paving segregation. The performance of segregated mixtures was evaluated in terms of moisture susceptibility, cracking resistance, fatigue life, raveling, and rutting resistance. The results of the investigations indicated that finer mixtures due to production segregation and coarser mixtures due to paving segregation were highly susceptible to moisture damage, raveling, and fatigue. In addition, the rutting potential for both production and paving segregation was higher for finer mixtures than coarser mixtures. The overall ranking of the performance parameters showed that finer mixtures resulting from production segregation had an inferior performance, whereas coarser mixtures resulting from paving segregation performed poorly relative to the control asphalt mixture.