Evaluation of Polyester Grout for Use in Dowel Bar Retrofit Treatments

Dowel bar retrofit (DBR) is an effective concrete pavement preservation technique to restore the load transfer efficiency at joints of the jointed plain concrete pavement. So far, more than 5 million dowel bars have been installed in the United States. Although the majority of DBR projects were successful, some have had issues, including early failures. Recently, it has been proposed that polyester grout may perform better than conventional DBR grout materials. Polyester grout is a grout using polymerized resin as a binder instead of fast setting concrete backfill material. Compared to conventional grout materials containing high alumina or magnesium phosphate materials, the polyester grout has more flexibility, better adhesion with the existing pavement, and a low viscosity for better consolidation. This paper presents the results of evaluation of performance of US 50 DBR project constructed with polyester grout in 2010 for the California Department of Transportation. In 2012, a team of researchers and engineers conducted visual inspections and nondestructive tests. Core extractions were also performed at a later date based on the visual inspection and non-destructive test results. In the laboratory, the tests included shear bonding strength tests as well as dowel bar pull out tests. The results in both the laboratory and field showed that the polyester grout has worked very well to date.