Aging Kinetics Characteristics of Warm Mix Asphalt Binder Using Softening Point and n-pentane Asphaltene Content as the Parameters

This paper presented research on the aging kinetics characteristics of asphalt binder by using softening point and n-pentane asphaltene content, respectively, as parameters. Sasobit additives were added into two matrix asphalt binders to prepare the warm mix asphalt binders, and then were aged at different temperatures and time. The softening points and contents of n-pentane asphaltene were measured. Results indicated that the softening point was improved by adding the additives. Both the softening point and content of n-pentane asphaltene increased with aging temperature and aging time, and the increments of matrix asphalt binders were bigger. Taking the softening point and content of n-pentane asphaltene as the parameters, respectively, the aging kinetics models were established, and the reaction rate constants and reaction activation energies were calculated. It was found that warm mix asphalt binders had lower reaction constants and bigger reaction activation energies, that is to say the anti-aging property of warm mix asphalt was better. The anti-aging properties could be better evaluated by the aging kinetics models based on the softening point for its higher accuracy and testing convenience.