Evaluation of Hot-Mix Pavement Performance in Northeast Texas (0-4104-S)

In 1995, a joint industry! Texas Department of Transportation (TxDOT) task force was established to identify issues associated with the unsatisfactory performance of hot-mix asphalt (HMA) layers made with siliceous river gravels in northeast Texas. To address the moisture susceptibility problem the team proposed a series of recommendations, including tighter aggregate specifications, use of anti-stripping agents, and use of modifiers. In the late 1990s these recommendations were implemented, on a trial basis, in several paving projects in the Atlanta District. In 1998, 35 sections were identified for tudy; they included some sections that had adopted the new recommendations and some that had not. These sections were field tested in late 1998 using both visual inspections and laboratory testing of field cores. The results were reported in TxDOT report number DHT-46, Evaluation of the Factors Affecting Moisture Susceptibility of Pavements in Northeast Texas. In general this project validated that the original recommendations produced improved HMA performance. As the sections were very young at the time of the 1998 surveys, a follow-up study was initiated in 2001 to provide a longer-term view of performance.