A full-scale experiment on introducing sulfur as a partial replacement for asphalt in road-paving mixtures was conducted in Kuwait. Laboratory and field testing programs were designed and carried out to analyze and investigate the results of this experiment. The optimum sulfur percentage in the sulfur-asphalt binder and the optimum binder content were established for the investigated mixtures at various curing ages. These mixtures were used in constructing two sections, each 0.67-mi long, of the driving lane of a main road. The first one, considered a control section, was constructed using the conventional asphalt concrete mixture. The second was the test section in which the sulfur-asphalt mixture was used in the entire pavement structure. The sulfur-asphalt mixture was found to significantly reduce rutting on the road. This was established in both field and laboratory investigations. Laboratory-aged samples showed longer fatigue life (indirect tensile stress control fatigue test). Inclusion of sulfur in the mixture was also shown to improve Marshall stability, indirect tensile strength, and the rate at which strength was gained during curing. On the other hand, including sulfur made the mixture moresusceptible to loss of stability on immersion in water and to having a lower resilient modulus at higher temperatures (above 95 deg F).Field Dynaflect measurements showed higher deflections for the roadtest section than for the control section.(A).
Abstract