Evaluation of temperature sensitivity of recycled asphalt based on numerical analysis model and thermal analysis kinetics

Abstract

The use of recycled asphalt not only consumed a large amount of reclaimed asphalt pavement (RAP), but also brought significant economic and social benefits. However, recent research mainly focused on the engineering properties of recycled asphalt, without paying attention to the temperature sensitivity of recycled asphalt in service. At present, the temperature sensitivity of asphalt was mostly studied in matrix asphalt, while the quantitative analysis of the temperature sensitivity of recycled asphalt was still lacking, and this study aimed to propose an effective quantitative analysis method of temperature sensitivity of recycled asphalt. For this, a self-developed rejuvenator was used to prepare recycled asphalt, and then the recycled asphalt was analyzed by conventional performance test, rotational viscosimeter (RV) test, dynamic shear rheometer (DSR) test and differential scanning calorimetric (DSC) test. The results showed that the temperature sensitivity of aged asphalt was improved by the addition of rejuvenator, and several evaluation indexes suggested that the temperature sensitivity of recycled asphalt was influenced by the dosage of the rejuvenator, to have excellent temperature sensitivity, a reasonable dosage of rejuvenator should be selected for recycled asphalt. In addition, the VTS equation most applicable to recycled asphalt was selected by the gray relation analysis (GRA) model, and the temperature sensitivity index most applicable to recycled asphalt was evaluated by principal component analysis (PCA) model. Finally, considering that the temperature sensitivity indexes were derived from the matrix asphalt, to more effectively study the temperature sensitivity of recycled asphalt, based on the DSC test, thermal analysis kinetics was used to analyze the test results, and an effective quantitative analysis method of temperature sensitivity of recycled asphalt was proposed.