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.
Transportation agencies will benefit from a guide for implementing performance specifications for both asphalt pavement and portland/alternative cement concrete. The transition from current QA practices that often rely on properties such as aggregate gradation or mixture volumetrics to practices based on performance criteria will be challenging and will introduce new risks for the state DOTs and contractors. Providing comprehensive guidance to the DOTs on the impact of performance-related and -based testing on the core elements of QA will help this transition occur in a controlled fashion and could help minimize risk to both parties during the implementation process.
The objective of this research is to develop a guide to assist state DOTs and industry in implementing performance specifications for asphalt pavements and portland/alternative cement concrete. The research shall focus on the integration of tests and procedures used in performance specifications into QA systems.
The guide shall specifically address, but not be limited to, implementation activities such as using pilot projects and shadow specifications, establishing appropriate control and specification limits, gaining buy-in from agency and industry personnel, and managing risk.
The research excludes development, refinement, or modification of specific performance tests.
Phase II is underway.