Study on micromechanisms of macro evaluation indexes for asphalt based on grey relation analysis

Abstract

ABSTRACT Macro evaluation indexes (penetration, ductility and softening point) are considered as an important basis for rational evaluation of asphalt service performance, but their micromechanisms have not been further studied. Thus, in order to establish the micromechanisms of macro evaluation indexes for asphalt, grey relational analysis and molecular dynamics simulation were applied to the study. Based on the measured data, the macro evaluation indexes and the variation of asphalt components were analysed. Combined with the characteristics (bond energy and non-bond energy) of asphalt 12-component molecules, the relationship among macro evaluation indexes, asphalt components and asphalt 12-component molecular were analysed by grey relation. Correlation coefficients of different scale characteristics were calculated, and their relationships were defined. The results show that the correlation degree of asphalt components and macro evaluation indexes is asphaltene > resin > saturate > aromatic. The relationship of intramolecular bond energy and macro evaluation indexes is closer than that of intermolecular non-bond energy. Additionally, macro evaluation indexes can be reasonably explained by component molecules to form micromechanisms. The study results have a certain theoretical and practical value for rational evaluation and understanding of service performance for asphalt materials and provide a theoretical basis for anti-ageing, modification and rejuvenation of asphalt.