Main Article Content
Abstract
The primary objective of this project was to develop a test for measuring the bond strength between pavement layers. The research was also to evaluate tack coat materials and application rates for the Alabama Department of Transportation (ALDOT). The project included a laboratory phase and a field phase. For the laboratory work, the experiment included two types of emulsion (CRS-2 and CSS-1) and a PG 64-22 asphalt binder that are allowed by ALDOT’s specifications. Bond strengths were measured with a shear type device at three temperatures and three normal pressure levels. Three application rates that encompassed the specification range were investigated for each tack coat. Laboratory prepared mixture samples included a coarse-graded blend and a fine-graded blend to represent two different surface textures. The effects of tack coat type, application rate, mixture type, testing temperature and normal pressure on the bond strength were evaluated.