ABSTRACT
Maintaining adequate level of skid resistance on highways is essential for the safety of motorists. Among other factors, skid resistance of asphalt pavements depends on aggregate shape characteristics and its resistance to abrasion and polishing. This study investigated the effect of aggregate blending on improving the frictional characteristics of asphalt pavements. Test slabs prepared using different blends of limestone and gabbro were subjected to accelerated polishing. Gabbro is known to have better resistance to abrasion and polishing compared to limestone. A dynamic friction tester was used to measure the coefficient of friction at different polishing cycles; in addition, the macrotexture was measured using a sand patch test. The results showed that blending gabbro with limestone would improve the frictional characteristics of asphalt mixtures compared to the control mix prepared with only limestone. Based on the findings of this study, a blend of 50% gabbro and 50% limestone would provide comparable skid resistance and cut down the amount of gabbro imported for road construction leading to cost savings and maximizing the use of natural resources in Qatar. Meanwhile, the researchers recommend constructing trial test sites and monitoring their frictional characteristics alongside evaluating the mechanical properties of the proposed blend to ensure durability.
