Verifying the Indirect Tensile at High Temperature (IDT-HT) Test Performance Criterion: A Multi-scale Investigation Integrating Laboratory, Full-Scale Accelerated Pavement Testing, and Field Evaluations

About the project:

The Virginia Department of Transportation (VDOT) has implemented the indirect tensile test at high temperature (IDT-HT) test as part of its balanced mix design (BMD) specifications to evaluate and screen out rut-susceptible dense-graded asphalt surface mixtures with A and D designations. The similarities with the indirect tensile cracking test (IDT-CT) make the IDT-HT a more practical alternative for rutting evaluation of asphalt mixtures compared to the asphalt pavement analyzer (APA) rut test. A previous study conducted by the Virginia Transportation Research Council (VTRC) recommended a performance threshold of 133 kPa for IDT-HT strength values based on specimens conditioned in an environmental chamber. This criterion was further refined to 100 kPa for water-bath conditioning. The water-bath method is attractive as it expedites specimen preparation process in comparison with the environmental chamber. The 100 kPa criterion was established by leveraging the relationship in IDT-HT strength values between the environmental chamber (i.e., dry) and water bath (i.e., wet) conditioning methods. Despite the strong correlation between dry and wet strength values, a limited number of asphalt mixtures was available during that study. Therefore, additional research is needed to verify and/or refine the IDT-HT performance criterion. 

Project Team

Principal Investigators