Project Details
RESEARCHERS
Shreenath Rao
SPONSORS
NCHRP, AASHTO, FHWA
KEYWORDS
Asphalt mixtures, Concrete, Guidelines, Impacts, Implementation, Performance measurement, Quality assurance (QA), Specifications, Test procedures
Project description
Many state departments of transportation (DOTs) are implementing performance specifications for asphalt pavements and portland/alternative cement concrete. This is being done to improve long-term durability, encourage contractor innovation, better align design requirements with construction, and introduce rational pay adjustments tied to predicted project life. Ongoing initiatives such as Performance Engineered Concrete Mixes for portland/alternative cement concrete and Balanced Mix Designs for asphalt pavements lend themselves to a performance specification approach by introducing higher level test methods more directly related to material performance. Introduction of these test methods and mix design criteria will have a major impact on existing quality assurance (QA) programs. Agencies will need to make informed decisions regarding applicability of new tests to process control, quality control, and acceptance. 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. Technician training and certification programs will need to be addressed, as will laboratory qualification and accreditation programs. Independent Assurance (IA) procedures will need to be developed and the impact on dispute resolution programs assessed. Precision and bias of the newer test methods will need to be determined, along with appropriate specification limits for various quality characteristics. New approaches to pay adjustments will need to be developed.