NCHRP, AASHTO, FHWA
Asphalt mixtures, concrete, Guidelines, Impacts, Implementation, Performance measurement, Quality assurance, Specifications, Test procedures
Many public transportation agencies are in the process of implementing some type of performance specifications for asphalt mix and concrete. Reasons for doing so include a desire to improve long-term durability, encourage contractor innovation, better align design requirements with construction, and to have rational pay adjustments tied to predicted project life. Ongoing initiatives such as Balanced Mix Designs for asphalt mixes and Performance Engineered Concrete Mixes lend themselves to a performance specification approach by introducing higher level test methods that are intended to be more directly related to material performance than current methods. Introduction of these test methods and mix design criteria will have a major impact on existing quality assurance programs. Agencies will need to make informed decisions regarding applicability of new tests to process control and quality assurance. Lot and sublot sizes may need to be adjusted to account for test time and complexity. Quantity of material obtained for testing may need to be increased.