Determination of Constructed Pavement Layer Thicknesses Using Nondestructive Testing (NDT)

Using nondestructive testing (NDT) to measure the thickness of pavement layers can improve the overall life of a new concrete and/or asphalt pavement. Conventional test methods require the extraction of a core from the pavement section to verify its thickness. Currently, two NDT technologies are commercially available which eliminate or reduce the need to core the existing pavement for thickness verification. The MIT-Scan-T2 (T2) utilizes magnetic pulse induction coupled with preset metal plates to obtain a thickness value. Measurements can be obtained quickly to an accuracy of +/– 2 mm. Ground Penetrating Radar (GPR) uses electromagnetic radiation to determine pavement layer thickness. However, GPR data need to be calibrated with an actual core during the post-processing phase to obtain the highest accuracy. Additionally, the dielectric properties of pavement sections being assessed with GPR must first stabilize to accurately measure thickness. Generally, stabilization occurs approximately 28 days after the initial placement of the pavement