Performance-Graded Binder Specification for Surface Treatments

Abstract

Surface treatments have been used by many government agencies as part of their maintenance and rehabilitation programs to improve surface quality and extend the service life of pavements. Traditional specifications for surface treatment binders have failed to characterize materials across the entire spectrum of temperatures experienced during production and construction and in-service and required properties that were not directly related to performance. The Superior Performing Asphalt Pavements (Superpave®) or performance-graded (PG) asphalt binder specification was developed in the 1990s to measure binder properties directly related to hot-mix asphalt concrete (HMAC) performance. This specification included material characterization at low, intermediate, and high temperatures. Direct application of the PG binder specification to binders used in surface treatments is not appropriate because of differences between surface treatments and HMAC with regard to distress types, construction methods, and exposure to environmental conditions. A performance-based specification system for surface treatment binders was developed that maximizes the use of existing equipment required in the PG system for HMAC binders. This new surface performance grading (SPG) specification assumes appropriate design and construction practices and considers only binder properties after construction. The SPG was developed based on the identification of common distresses and the analysis of physical properties at multiple temperatures of surface treatment binders that correlate to these distresses. The final SPG includes limiting values for high-and low-surface pavement design temperatures. Implementation of the SPG specification is recommended after a field validation experiment.