A FOLLOW-UP EVALUATION OF HOT-MIX PAVEMENT PERFORMANCE IN NORTHEAST TEXAS

A task group was formed in late 1997 to evaluate the specifications and practices being used in northeast Texas districts in the construction of hot-mix asphaltic concrete pavements. Specifically, the objective of that task group was to determine if the implemented recommendations from a 1995 task group were effective in improving the performance of crushed gravel asphaltic pavements in that area of the state. The task group selected and evaluated the performance of 35 pavements constructed using a wide variety of materials over the prior nine years. Seven of the pavements had been constructed in 1997, some of which had incorporated a number of the earlier task group recommendations. Pavement performance evaluations in early 1998 included a visual distress survey, ground-penetrating radar analysis, pavement management information system data, and testing and visual evaluation of pavement cores. The early age of pavements evaluated in the spring of 1998 prevented a definitive determination of the long-term performance of northeast Texas asphalt pavements. Therefore, the task force recommended evaluation of the performance of these sections in three years. In the spring of 2001 the task force was reconvened to conduct the follow-up study on the 35 pavements evaluated in 1998. The task force was composed of personnel from Atlanta, Tyler, and Lufkin districts as well as representatives from Design and Construction Divisions, the Research and Technology Implementation Office, Texas Transportation Institute, and two consultants. The study presented in this report indicates that many of the recommendations implemented in 1997 by the Atlanta District have resulted in improved pavement performance. Utilization of hydrated lime as an antistripping additive appears to have a positive influence on performance of the mixtures containing crushed siliceous river gravel. It is recommended that the findings of the 1995 task group be considered for implementation by all districts that use crushed siliceous river gravel in hot mix.