Performance Report on Jointed Concrete Pavement Rehabilitation Strategies in Texas (05-0292)
Dar-Hao Chen, Texas Department of Transportation

Reflective cracking through JCP overlays has been a persistent problem. Several different rehabilitation strategies have been used in Texas. This paper provides a summary of the performance of strategies used in the past 10 years. The performance of crack retarding grid has been disappointing. It has caused several premature failures through debonding. Only one project has realized a benefit of Crack retarding grid, where the reflective cracking was delayed by about 1 year. The authors thought the small openings in the Crack retarding grid and the lack of an effective bond may be the causes of the debonding. Propriety crack retarding asphalt material (Strata ®) has been performing well over 2 years of monitoring. In one experimental project, 100% of the cracks reflected through conventional overlay material in the first year. Both Petromat fabric underseal and Strata ® have been performing satisfactorily to retard reflective cracking. However there was a large cost difference between these two treatments. This paper will also discuss the findings from an evaluation of 7 experimental treatments on a major experiment on US 59 in the Lufkin District. The worst performing section on the US59 project was the break-and-seat method that failed due to weak subgrade support. The weak subgrade is unable to support cracked concrete, which leads to a rocking action under traffic loads. It is concluded that for future projects, the break-and-seat method should not be applied on subgrade with DCP penetration rate exceeding 25mm per blow. Flexible base overlay with thin asphalt surfacing and the Arkansas (large stone) mix have performed well. Flexible base overlays were able to absorb the joint movement and eliminate the reflective cracking. Through lab characterization it was found that the flexible base should be of top quality with very low moisture susceptibility. In Texas, this involves specifying a Texas Triaxial Class 1 material with classification of “Good” in suction/dielectric tests. It is critical to provide an effective seal for the flexible base. A chip seal followed by a thin 75mm hot mix layer is recommended.