Influence of curing agent ratio, asphalt content and crosslinking degree on the compatibility and component distribution of epoxy asphalt in compound curing agent system

To study the effects of curing agent ratio, asphalt content, and crosslinking degree on the properties and distribution of epoxy asphalt with a compound system of dicarboxylic acid and acid anhydride, epoxy asphalt molecular models with two asphalt contents of 25% and 65% and three curing agent ratios of 10:1, 5:1 and 1:1 were constructed by Materials Studio. Various epoxy resin crosslinking degrees were further realised by Perl language crosslinking script. Glass transition temperatures were calculated to characterise low temperature flexibility. Energy systems and interaction energy were simulated to characterise the compatibility of epoxy asphalt. The radial distribution function (RDF) was calculated to observe the composition distribution of epoxy asphalt. The results show that the raise of the crosslinking degree and the proportion of anhydride curing agent increased the Tg of epoxy asphalt, impairing the low temperature performance. The increase in asphalt content was beneficial to the stability of the epoxy asphalt. Resin-based epoxy asphalt had stronger interaction between epoxy resin phase and asphalt phase, and the interaction energies both reached the maximum values at crosslinking degree of around 25%. Resin-based and asphalt-based epoxy asphalt had the most notable composition difference in the distribution of asphaltenes and acid anhydrides.