Implementation of Performance-Based Specifications for Asphalt Mix Design and Production Quality Control for New Jersey

To help improve the performance of the asphalt mixtures being placed on New Jersey roadways, the New Jersey Department of Transportation (NJDOT) has developed a Performance-Based Mixture Design and Quality Control program. The basis of the program is to “engineer” asphalt mixtures for specific performance needs. This approach is an improvement over the current mentality that the same asphalt mixture can be placed on all applications and be expected to perform as intended. This paper highlight’s NJDOT’s performance-based asphalt mixture design system for their asphalt mixtures. These mixtures, comprising of approximately 10% of the total asphalt tonnage placed in the state, are selected based on the extreme needs of the pavement structure in question. Each of these performance-based mixtures is required to undergo performance testing during the mixture design, test strip, and project construction phase to ensure the final mixture achieves the desired performance to the specific pavement structure. Although the NJDOT has only begun to implement the performance-based asphalt mixtures since 2008, monitored field performance of these mixtures has indicated that these materials are all performing exceptionally well, and in some cases, performing far beyond what conventional NJDOT asphalt mixtures are capable of. While New Jersey’s hot mix asphalt suppliers/contractors were skeptical and somewhat reluctant to begin this new age of performance-based asphalt mixtures, they understand New Jersey’s need for these mixtures and have embraced their use. As the performance-based mixtures have become more widely accepted and the methodology of design and production becomes more efficient, it is hopeful that New Jersey will be able to implement some form of performance-based for all asphalt mixtures.