Evaluation of the performance of basaltic aggregates in stone mastic asphalt and dense-graded asphalt concrete mixtures

In this study, the usability of aggregates supplied by four quarries in Erzurum and Ağrı regions in stone mastic asphalt pavements and densely graded asphalt concrete was investigated. Mineralogical, petrographic, and chemical analyses were conducted for the supplied aggregate samples, and their physical and mechanical properties were determined through experiments. Bitumen and aggregates with predetermined properties using the Marshall design method, dense-graded asphalt concrete and stone mastic asphalt mix designs were prepared for the wearing course in accordance with the General Directorate of Highways' technical specifications. Optimum bitumen content was determined separately for dense-graded asphalt concrete and stone mastic asphalt for each quarry and asphalt mixture samples with the specified bitumen contents were prepared and evaluated for water damage, deformation, low-temperature cracking, and low-temperature strength. For this purpose, modified Lottman (AASHTO T283), indirect tensile strength, cyclic load creep, and semi-circular bending tests were conducted. It was found that there was a significant difference in asphalt mix performance among the quarries, and stone mastic asphalt mixes showed higher water damage, deformation and cracking resistance than dense graded asphalt mixes, both when the same aggregate was used and when different aggregates were used for the selected quarries.