Assessment of Mitigating Transverse Joint Faulting on Portland CementConcrete Pavement with Polyurethane Foam on LA 1 Bypass, State ProjectNumber 034-30-0023

A case study was conducted by the Louisiana Transportation Research Center (LTRC) to assess the effectiveness of reducing faulting on jointed concrete pavement (JCP) with polyurethane foam (PF) on LA 1 Bypass, S.P. 034-30-0023. The PF fault correction process entailed reducing faults to approximately 0.25 inches by saw cutting full depth through the joints and lifting the slabs with PF whose free rise density was 6 pcf. A sampling plan was established where the entire project was measured for faulting and roughness by a high speed profiler before treatment with the PF fault correction process and 0.6, 2.1, 3.4, and 4.4 years after treatment. Three test sections with 11 slabs each were assessed with the falling weight deflectometer (FWD), ARRB walking profiler, and manual fault measurements. Seventeen cores were taken at various locations to obtain in-place PF samples. Statistical hypothesis testing was conducted comparing the density and strength of PF before and after it was injected into the pavement. Testing results indicated that repair goals of reducing faults were realized by the PF fault correction process, but at the sacrifice of severely reducing load transfer efficiency (LTE) at the transverse joints. Service life extensions of approximately 6.0 and 8.3 years on the north and south bound roadways, respectfully, for fault height reduction were discovered. Unfortunately, the PF fault correction process severely impacted the LTE with 80 percent of joints having poor load transfer, 20 percent increase of joints needing load transfer improvement, and 0 percent of the joints in good condition. Deflections at the joints and center-intermediate slab locations were increased as much as 46 percent by the PF process indicating lower strength conditions. Void potentials were increased slightly (8 percent) by the process. The estimated service life extension based on the international roughness index (IRI) parameter was 3.1 years and 5.7 years for the north and south bound roadways, respectively. Taking into account all the parameters analyzed in this study, the PF fault correction process was not recommended as a pavement preservation treatment for fault correction or ride quality improvement due to the detrimental effects discovered in this study.