Title: A Comparison of Nondestructive Methods for Detecting Reinforcing Bar Placement (Pre-Published)

Author(s): David C. Burney, Kimberly E. Kurtis, Laurence J. Jacobs, and Ryan J. Sherman

Publication: Materials Journal

Volume:

Issue:

Appears on pages(s):

Keywords: cover; dowel; eddy current; epoxy-coated; galvanized; GPR; QA; stainless-steel

DOI: 10.14359/51742260

Date: 9/13/2024

Abstract:
Despite improvements in nondestructive testing (NDT) technologies, the quality assurance of concrete reinforcing bar (rebar) placement is still primarily conducted with conventional methodologies, which can be time-consuming, ineffective, and damaging to the concrete components. This study investigated the performance of two commercially available cover meters and one ground penetrating radar (GPR) device. A cover meter was found to have the greatest accuracy for depths smaller than 3.19 in. (81.0 mm), while the GPR performed better for greater depths. The effect of reinforcing bar depth, diameter, and type; neighboring reinforcing bar; and concrete conditioning on the performance of the devices was quantified. The use of epoxy-coated reinforcing bar, galvanized reinforcing bar, and stainless-steel reinforcing bar was found to have a negligible effect on cover meter accuracy. A model was developed to predict the precision of the GPR post-measurement analysis given a depth and concrete dielectric constant.