Research Article Transportation Research Record 2023, Vol. 2677(1) 1259–1275 Ó National Academy of Sciences: Transportation Research Board 2022 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/03611981221103871 journals.sagepub.com/home/trr Non-Destructive Testing in Quality Assurance of Concrete for Assessing Production Uniformity Setare G. Saremi 1 , Dimitrios G. Goulias 1 , and Anjuman Ara Akhter 1 Abstract Non-destructive testing (NDT) methods can be particularly valuable in assessing concrete quality at early ages as they are associated with reduced testing time and cost. A national study focusing on the potential use of NDT in quality assurance (QA) of concrete has recommended the adoption and/or use of such testing methods when these have low level of testing variability. Thus, objective of this study was to build on such recommendation and assess the response of specific well- developed and mature NDT methods in relation to their testing variability for detecting such production defects such as hon- eycombing and segregation. Recognizing the extensive knowledge and experience in assessing concrete with such methods over the years, the selected NDT methods considered were: ultrasonic pulse velocity (UPV); resonant frequency analysis (RFA); and, rebound hammer. Each of these NDT methods could be used for a specific assessment within QA as identified later on within the manuscript. The results indicated that indeed UPV is able to identify the presence of such defects with acceptable accuracy and repeatability. RFA also provided acceptable testing variability and thus can be used as complementary assessment to UPV in both lab and field-cured samples. The rebound hammer, as expected, was characterized with high test- ing variability and thus its use could be limited to a quick and only initial forensic assessment. Overall, the use of these NDT methods in QA will provide the opportunity to test a larger portion of concrete without a significant increase in QA cost and testing time. Keywords infrastructure, construction, quality assurance management Timely detection of deterioration and/or poor construc- tion quality of concrete in structures has been a goal of highway and civil engineers for many years. Following the recommendations of a recent national study underta- ken for the Federal Highway Administration (FHWA) on the development of non-destructive testing (NDT)- based quality assurance (QA) processes for concrete materials, the need to assess such methods was identified (1, 2). For NDT methods to be used in QA, and/or acceptance testing specifications, they should be fast, accurate, reliable, and simple to perform for both owners and contractors. The required speed, accuracy and relia- bility of NDT for QA was assessed in the FHWA study for many available methods. A ranking system was developed with relative weights for reflecting the impor- tance of cost, repeatability, and ease of use of these methods (3, 4). The NDT methods examined in this study achieved high marks for adoption in an NDT- based QA, because of ease of use with minimal training for testing and data interpretation, and affordable instru- mentation cost (1). These included: ultrasonic pulse velo- city (UPV) and resonant frequency analysis (RFA) methods, and rebound hammer. The suggested guide- lines of how these methods can be implemented in an NDT-based QA plan by state departments of transporta- tion were described in other publications (1, 2), which included information on testing conditions, frequency, operator expertise and training, and associated costs, 1 Department of Civil & Environmental Engineering, University of Maryland, College Park, MD Corresponding Author: Setare G. Saremi, sghahris@umd.edu