Comparison of two pavement rehabilitation strategies

The main objective of the most recent Mobile Load Simulator (MLS) test program was to conduct a comparative study of two rehabilitation processes, Rehabs A and B, constructed on the south- and northbound lanes of US281 near Jacksboro, Tex., in 1995 and 1996, respectively. The underlying pavements have composite asphalt layers with the first construction done in 1957. Performance was evaluated in terms of surface rutting, loss of stiffness in pavement layers, and permanent deformation in the layers. Tools used during the study included an on-site weather station, nondestructive testing equipment (FWD, SPA, PSPA, SASW), and in situ instrumentation (MDD). The findings of this study provided conclusive results on the relative performance of the two rehab strategies. Rehab A performed well with its sound underlying structure. The Dallas District has elected to use this recycling process based, in part, on the results of the MLS tests in Jacksboro. The study serves as an example of how the MLS program has yielded a variety of products and increased pavement engineering knowledge.