Ranking low temperature cracking performance of asphalt binders based on limiting phase angle temperatures and stress relaxation properties

The resistance of asphalt binder to low temperature cracking is critical in ensuring the durability of pavements in cold climates. Although the extended bending beam rheometer (EBBR, AASHTO T 406) test is generally effective, it requires a large quantity of material and is time consuming. This study aims to develop a simplified method for assessing low temperature performance using a dynamic shear rheometer (DSR). Thirty different binders were tested using both EBBR and DSR test protocols. The results show that several parameters derived from the DSR test, such as the limiting phase angle temperature, the stress relaxation rate (m_r) after slow cooling, and the equivalent grade temperature from the stress relaxation test, exhibit strong correlations with the EBBR limiting low temperature performance grade (LLTPG). Furthermore, the stretched exponential factor (β) and the characteristic relaxation time (τ), obtained from the Kohlrausch-Williams-Watts (KWW) function, have proven to be useful indicators for low temperature performance. These findings suggest that DSR testing can serve as a practical alternative to the EBBR protocol, offering a practical approach to ensuring asphalt pavement resilience in cold regions.