Innovative Sprinkle Treatment for Thin Durable Asphalt Overlays

This paper presents techniques for improving asphalt overlays through the use of innovative surfacing technologies that employ durable local aggregates spread on a cost-effective wearing surface base mixture. A few states have used the sprinkle treatment to improve the skid resistance of pavement surfaces on top of typical asphalt pavements. Numerous approaches have been introduced to improve the performance of asphalt pavement. These improvements often add cost because they use high-quality aggregates and modified binder. Because sustainable and cost-effective pavements are being emphasized, innovative application of the sprinkle treatment has been considered. A fine-graded dense asphalt wearing surface mixture developed with the Bailey method provides a promising aggregate structure that makes it possible to ensure compactibility with relatively thinner layers of asphalt mixture. The design of the base mixture used less-expensive local aggregates, and its performance was compared in the laboratory with that of two control mixtures to evaluate durability, rut resistance, moisture susceptibility, fracture, and complex modulus. To evaluate the performance of sprinkle treatment pavements under real traffic loading, test pavements of various thicknesses were constructed in northern Illinois during October and November 2010. On-site performance tests that included noise, friction, rut depth, and texture profiles were conducted at 4-month intervals after construction. The study concluded that it is feasible to use a cost-effective alternative wearing surface that performs well.