Fast Screening of Weak Joints in Jointed Concrete Pavements with a Traffic Speed Deflectometer

Abstract: Traffic-speed deflection devices (TSDDs) have gained momentum as a pavement structural capacity assessment tool. Their value as a surveying device for network-level pavement management purposes has been demonstrated, and abundant literature regarding the structural evaluation of flexible pavements with TSDs has been published. Attempts to assess in-service rigid pavements with TSDDs, however, have started only very recently. Some mechanistic data interpretation schemes exist. However, a mathematically simple and computationally fast screening procedure is warranted to detect and report the location of structurally weak spots directly from TSDD data at the network-level for investigatory and project-level prioritization. This paper introduces one such technique to detect, locate, and rank transverse joints suspected to have deficient load-transfer capabilities using deflection velocity data from a Traffic-Speed Deflectometer (TSD), one type of TSDD. The quantitative metric for joints classification, nicknamed ABMx, is based on the amplitude of the normalized deflection velocity data sampled as the TSD rolls over the joint, and thus independent on the jointed pavement’s stiffness. To further validate the location of the detected weak joints, we appeal to transverse joint and transverse crack data collected simultaneously by a Laser Crack Measurement System (LCMS) mounted on the TSD vehicle.
We demonstrate the use of ABMx for weak joints screening with data collected at jointed concrete segments of the Interstate System. However, the use of ABMx can be extended to any kind of jointed pavement.