COMPARISON OF STABILITY AND VOLUMETRIC PROPERTIES OF CONVENTIONAL AND STONE MASTIC ASPHALT

This study experimented with and compared the performance stability, volumetric properties, and resistance to rutting of SMA and CMA under simulated traffic loads. It was found in the Marshall Stability Test that SMA can withstand much higher stability (15.8 kN) than CMA (10.6 kN), thus demonstrating that we are far more resistant to any plastic deformation. In addition, SMA demonstrated better flow values (3.2 mm vs. 2.7 mm) and density (2.34 g/cm3 vs. 2.28 g/cm3) indicating suitability for high-stress pavements. Volumetric analysis demonstrated that SMA has higher Voids in Mineral Aggregate (VMA: 17. These are better than CMA (VMA 15.2%, VFA 75%) in binder to aggregate ratio and stability (5%) and Voids Filled with Asphalt (VFA: 80%) compared to CMA (VMA: 15.2%, VFA: 75%). Additionally, SMA's lower air void content (VTM: 3%). Less water ingress and slower aging concerning CMA's 4.0% (vs. 0%) By minimizing binder loss and improving durability, the binder drainage rate of SMA (0.2%) was much lower than that of CMA (0.8%). It found that rutting resistance was higher for SMA (25.3 mm; 50,000 load cycles; 12.0% strain at failure) than CMA (30.6 mm; 50,000 load cycles; 14.2% strain at failure), demonstrating its long-term deformation resistance under heavy traffic. In addition, SMA proved to be stiffer (1500 N/mm vs. CMA’s 1200 N/mm) and better suited for high-traffic roads. SMA finally has superior performance, durability, and rutting resistance and therefore represents an excellent choice for heavily trafficked roads despite a somewhat higher initial cost than HMA, and because the life cycle cost of SMA pavement is lower than for HMA. This enhances properties to reduce maintenance and service life, resulting in cost-effective solutions for high-stress pavement applications. SMA's sustainability and affordability could be further improved if more research is undertaken into recycled materials and their environmental impacts.