Mitigating seal coat damage due to superheavy load moves in Texas low volume roads

Over the past few years, the number of Super Heavy Load (SHL) moves on the Texas highways has drastically increased, resulting in severe damage, particularly on low volume roads. One of the major failure modes on these low volume roads is peeling the fresh seal coats that have been employed as a primary maintenance option by the Texas Department of Transportation (TxDOT). In this paper, a mechanistic-empirical (M-E) guideline that incorporates a Microsoft Excel spreadsheet program was developed to aid in the evaluation and characterization of the damage (peel-off) potential of seal coats when subjected to SHL vehicle loading. Field validations were conducted to validate and calibrate the guideline. It was observed that the pavement surface temperature is the most critical factor along with pavement slope in travel direction, combination of aggregate and binder types, and curing period. Additionally, the texture depth that was measured using the sand patch test method was found to play a significant role in characterizing and controlling seal coat damage. Overall, the developed M-E guideline exhibits great promising potential to serve as an aid for evaluating and mitigating seal coat damage due to SHL vehicle loading on low volume roads in Texas.