Chemical and physical effects of polyurethane-precursor-based reactive modifier on the low-temperature performance of bitumen

•The results of the chemical analysis were consistent with the quantum-chemical calculations using known bitumen model compounds.•Based on the active sites provided by the asphaltenes and resins, carbamate, urea, and amide linkages were formed during the PRM modification.•The PRM modification promoted the reconfiguration of asphaltene and the conversion of the resin to asphaltene.•The PRM modification resulted in significant changes in the composition and chemical structure of bitumen.•The low-temperature performance of bitumen is expected to be improved by PRM modification.