Assessment of Long-term Performance of Pavements Containing Warm Mix Asphalt Technologies in Louisiana

Abstract

This study focused on the assessment of long-term performance of asphalt pavements containing warm mix asphalt technologies in Louisiana. A total of five rehabilitation projects were studied in the state of Louisiana. The study consisted of engineering desk analyses of field performance indicators, indices and the initial laboratory performance indicators measured for five rehabilitation projects. The engineering desk study consisted of a review of literature from previous WMA technology projects done in Louisiana. Additionally, data was acquired and validated from the Louisiana Pavement Management System (PMS). Pavement performance indicators (i.e., cracking (transverse, longitudinal, and fatigue cracking), roughness, rutting, and pavement indices and pavement condition index data acquired from PMS were analyzed using statistical methods. Furthermore, laboratory test data for mechanical performance indicators at the construction stage such as loaded wheel tracking (LWT) rut depth, semi-circular bend (SCB) Jc , flow number, and dissipated creep strain energy (DCSE) were obtained from LTRC database and published reports. Analysis to link initial laboratory mechanical performance indicators to field performance indicators were performed. In general, similar, or better pavement performance indicators for rutting and cracking (longitudinal, transverse, and alligator) was reported for WMA test sections compared to their companion hot mix asphalt (HMA) sections. Additionally, the LWT rut depth was found to be a better indicator of field rutting performance than the flow number parameter. It should be noted that SCB Jc parameter was found to correctly rank more field cracking indicators than the DCSE parameter and hence may be a better indicator of field cracking performance than the DCSE parameter. Additionally, the actual field performance indices for both Conventional HMA AND WMA test sections were similar or higher than the predicted indices based on LA DOTD performance curve formulae. Which indicates a better or similar distress performance after seven to ten years in service.