Performance of warm-mix asphalt in the highway industry

Warm-mix asphalt (WMA) technologies could address the problem of deterioration of roads, reduce escalated energy costs and increase environmental awareness. This technology allows significant reduction in temperature for construction and paving of roads compared to conventional hot-mix asphalt (HMA) paving. In HMA production, the quarry mixing and paving temperatures are equivalent to bitumen's viscosity of 170 and 280 cP, respectively, for a proper coating of aggregates and field paving. But in WMA, the viscosity of bitumen is reduced and increases the workability of the mixture. Sasobit and asphamin are the two major additives used with bitumen or in batching plant for the production of WMA. Besides, complex shear modulus (G*) is used to determine the rutting (G*/Sin delta) and fatigue factors (G*Sin delta) to control the deterioration of roads. A further study is needed to monitor the overall performance of WMA in the context of pavement temperature.