NCHRP, AASHTO, FHWA
Asphalt-based materials, concrete, Handbooks, Implementation, Nondestructive tests, Quality assurance, Quality control, Road construction, State departments of transportation, State of the practice
State highway agencies (SHAs) routinely accept highway materials using quality assurance (QA) procedures based on certifications and material requirements, material specifications (method, end-result and performance requirements) and acceptance plans. In most cases, the QA requirements consider the federal regulations for construction QA procedures 23 CFR, Part 637B, as well as the recommendations of the Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Officials (AASHTO) for QA programs. However, one thing generally missing in these programs or plans is the utilization of nondestructive testing (NDT) methods in the QA process. Several studies in recent years have identified the potential advantages of incorporating NDT methods into the QA process for highway materials. These methods are considered to provide an “added value” in the QA process since they enable (i) quickly assessing product uniformity in real-time as construction progresses; (ii) identifying potential defects during construction and thus allowing for timely corrective actions; (iii) inspecting/testing more frequently and replicating without the damaging effects of coring and other destructive testing; and (iv) reducing testing and inspection costs while improving construction quality and available data for SHAs to use in their acceptance process.