Low-Temperature Performance of Asphalt Mixtures: A Comparative Study of IDT and SCB Tests

Abstract: The Balanced Mix Design (BMD) approach in asphalt mixture design emphasizes optimizing both rutting resistance and cracking performance of asphalt concrete (AC). Among these concerns, low-temperature cracking is particularly critical, as it significantly affects pavement durability and service life. Relying solely on binder creep tests to assess low-temperature cracking issues in AC pavements has been proven inadequate. Various methods have been proposed to evaluate temperature-induced cracking in AC, including the Indirect Tensile Test (IDT), Semi-Circular Bend (SCB), and Disk-Shaped Compact Tension (DCT) test. However, the SCB and DCT tests are often cumbersome for routine use due to their complexity and equipment requirements. In contrast, the IDT test has already been widely adopted in the Superpave mix design framework to assess moisture susceptibility in Hot Mix Asphalt (HMA). This study aims to investigate the correlation between the IDT and SCB tests for assessing the low-temperature cracking performance of HMA mixtures. By comparing these test methods, this research seeks to establish whether the IDT test can serve as a simpler, more practical alternative to the SCB and DCT tests for low-temperature cracking evaluation. The findings will contribute to refining testing protocols, improving the practicality of low-temperature performance assessments, and enhancing pavement design strategies to ensure the durability and longevity of HMA pavements.