Rheological properties and microscopic mechanism of composite regenerated asphalt

To optimize the regeneration performance of waste cooking oil (WCO) as a single-component regenerant for aged SBS modified asphalt, a composite regeneration approach using diisononyl cyclohexane-1,2-dicarboxylate (DINCH) and WCO was employed. This effectively prevents excessive softening of the asphalt by WCO. Conventional performance tests were conducted on WCO regenerated asphalt to determine 4 % as the optimal dosage. The rheological properties of the asphalt were evaluated using Dynamic Shear Rheometer and Bending Beam Rheometer. The regeneration mechanism of aged SBS modified asphalt was revealed through the Fourier Transform Infrared Spectroscopy test and the Saturates, Aromatics, Resins, and Asphaltenes test. The experimental results demonstrated that compositing 4 % WCO with DINCH effectively restored the rutting resistance, non-recoverable creep compliance, and strain recovery rate of aged SBS modified asphalt. Moreover, the experimental findings highlighted that the aging effect could reduce the temperature-sensitivity of asphalt, but negatively impacting low temperature performance. The low temperature performance of aged SBS modified asphalt could be restored to the level of original asphalt when the DINCH dosage was 1.6 %. The Saturates, Aromatics, Resins, and Asphaltenes test results indicated that the composite regenerant effectively adjusted the proportion of aromatics and asphaltenes in the aged SBS modified asphalt, achieving prospective regeneration effects. The Fourier Transform Infrared Spectroscopy test results revealed that the component adjustment process did not involve a chemical reaction, indicating that the mechanism was physical blending.