UTC 2022 Funding - Cycle 2 Research Projects

Project No.: CY3-UTEP-04
Title: Establishing Applicability of TSD Measurements for Rigid Pavement Assessment
Performing Institution: The University of Texas at El Paso
Principal Investigator: Cesar Tirado, Cesar Carrasco, and Hector Cruz Lopez The University of Texas at El Paso
Start and Anticipated Completion Dates: 01/01/2026 to 01/15/2027 
Abstract: The Traffic Speed Deflectometer (TSD) offers significant advantages over traditional pavement evaluation methods like the Falling Weight Deflectometer (FWD) by enabling continuous, rapid assessment at traffic speeds, measuring deflection velocity profiles as opposed to the static deflection basins acquired by the FWD. However, the sensitivity of the TSD's laser Doppler sensors, particularly when applied to rigid pavements characterized by low magnitude deflections and inherent measurement variability, has hindered the reliable backcalculation of deflection parameters and consequently limited their usability for detailed structural evaluation. This research proposes to establish the applicability of TSD sensor measurements to establish means to estimate the structural integrity of jointed concrete pavements, in particular their load transfer efficiency. To that end, a comprehensive numerical simulation will be carried out to evaluate the impact of key rigid pavement parameters on measured deflection velocities to identify sensors that may be best suited for establishing relationships to estimate load transfer efficiency, with subsequent validation using existing field data from established test site databases. Ultimately, this research will provide pavement engineers with a clearer understanding of the capabilities of TSD technology for rigid pavement evaluation, enabling more informed decisions regarding its practical application in network-level structural assessment and the derivation of meaningful structural indicators. 

This study will employ a two-pronged approach. By means of numerical simulation, the dynamic response of rigid pavements under wheel loads will be developed, replicating the loading conditions of a TSD. This simulation will systematically investigate the influence of critical pavement parameters, such as slab thickness, modulus of subgrade reaction, joint stiffness, and the presence of anomalies.  The findings will then be validated using existing field data obtained from well-documented rigid pavement test sections where both TSD and FWD are available. By comparing simulated and measured deflection velocities and subsequently calculating analogous deflection indices, including a TSD-derived joint load transfer efficiency, the research will establish the conditions under which TSD data provides reliable information for rigid pavement assessment and determine the correlation and applicability of these new indices relative to established FWD-based indicators. 
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