Subsurface Condition Evaluation of Asphalt Pavement for Pavement Preservation Treatments

Abstract

Abstract The Indiana Department of Transportation (INDOT) has developed a guideline for evaluation of subsurface condition, a project-level evaluation for applicability of Indiana pavement preservation treatments (PPT). The developed guideline, using ground penetration radar (GPR) measurements, surface distress, and laboratory tests, determines the pavement subsurface distress severity and its distribution. The guideline also incorporates the newly developed water stripping severity test utilizing the digital image processing. The guideline has hierarchal evaluation system based on the type of data available for the test section. Level 1 is selected if GPR analysis data is available, level 2 is selected if surface distress data is available, and level 3 is used for all other cases. In addition, the subsurface distress distribution analysis tool (DCUAL) provides the locations of the PPT applicable sections. Case studies were conducted to provide aid to better understand the guideline, to present the example evaluation results upon the application of the guideline, and to validate the applicability of guidelines. Three test roads treated with PPTs within two to three years in Indiana were selected, and different evaluation levels were applied to the test roads. Level 1 and level 2 were applied for state road (SR) SR-70, and level 2 and 3 was applied for SR-257 and SR-43, respectively. Level 1 and level 2 analyses in the case study showed a good agreement with the case of the non-uniform subsurface distress distribution. In the process of determining the PPT applicability, pavements with the overall score of 60 or higher were found to be suitable for PPTs for all three levels of analysis and suitable for the Indiana State Roads having average annual daily traffic of less than 9000. Overall, the case study validated that the guideline provides a consistent, rational, and data-driven decision-making process for the applicability of the project-level pavement preservation program.