Rutting Resistance of Plant-Produced Modified Asphalt Mixtures: A Comparative Evaluation Using HT-IDT and Marshall-RT
摘要
The present study evaluated and compared the rutting performance of modified asphalt mixtures using the high-temperature indirect tensile strength (HT-IDT) test and the Marshall rutting test (Marshall-RT). These two tests can be performed using existing loading frames and the fixtures available in many asphalt pavement research and field laboratories. Eight different plant-produced dense-graded asphalt mixtures prepared with different modified binders were evaluated. The collected mixtures contain two different nominal maximum aggregate sizes (NMAS-13.2 mm and 19.0 mm) and modified binder types (highly modified asphalt [HiMA], polymer-modified binder [PMB], and crumb rubber-modified binder [CRMB]). The test samples were compacted to 7 ± 0.5% air void content using a Superpave gyratory compactor. The rutting resistance of the HiMA and PMB mixes was consistently higher than those containing the CRMB in the HT-IDT and Marshall-RT tests. The test results showed that HT-IDT and Marshall-RT had a strong linear agreement. Based on the correlation developed, the minimum values were calculated for Marshall-RT parameters [peak load (Pmax) and work done for the deformation damage ( \(W_{{P_{{{\text{max}}}} }}\) )] as 3.6 kN and 9.2 kN-mm, respectively. Both tests screened the asphalt mixtures similarly, and the coefficient of variation (CoV) was less than 10% for most of the mixtures evaluated, indicating higher repeatability. Therefore, both HT-IDT and Marshall-RT tests can serve as surrogate tests and effectively used during mix design and plant production phases as quality control (QC) and quality assurance (QA) tools.