Rigid Pavement Evaluation System: Implementation of RMODS (1939-3F)

RMODS is a rigid pavement evaluation and backcalculation system developed by the Texas Transportation Institute for the Texas Department of Transportation. The system processes Falling Weight Deflectometer data to generate information on the structural strength of the concrete slab and the subsurface support. Outputs from the system include:a. the elastic modulus of each layer,b. the modulus of subgrade reaction (k) and characteristic length (lk) for center slab or edge loading,c. the load transfer efficiency of joints or cracks, and d. the presence of voids beneath joints.This report provides the technical background to RMODS. The backcalculation models included are the Hertz and linear elastic models for processing center slab deflection data and the Westergaard model for processing free edge deflection data. The void detection procedures included both the methods proposed by the Center for Transportation Research (CTR) and the National Cooperative Highway Research Program (NCHRP).Case studies conducted on several in-service concrete pavements are also included.