A Differential Scanning Calorimetry Study of Asphalt Binders

This is an examination of the use of Differential Scanning Calorimetry (DSC) for studying the thermal properties and behavior of asphalt. DSC provides parameters for comparing the glass transition temperatures, endothermic behavior of asphalt fractions and whole asphalts, aging, slow cooling and heat rate effects of 8 SHRP (Strategic Highway Research Program) core asphalts and several other asphalts. DSC testing indicates that naphthene aromatics contribute heavily to the endothermic effect of the parent asphalt. Polar aromatics show a small endothermic effect at similar temperature ranges. Asphaltene, due to its chemical nature, shows no endothermic effect. The thermal behavior of saturates is not clearly understood. Test results also show that the higher molecular weight of the No 1 fraction, the smaller the endothermic peak will be. Test results suggest that the average linear side chain length may be a key parameter affecting endothermic behavior.