Asphalt　can　deteriorate　and　age　due　to　exposure　to　environmental　conditions.　This　ageing　reduces　pavement　performance　and　recycling　waste　pavement　is　relevant　for　environmental　protection.　The　oxidation　process,　properties　and　interfacial　behaviour　of　asphalt　binders　and　foamed　asphalt　binders　were　discussed　with　the　classical　molecular　dynamics　(MD)　simulation　and　reactive　force　field　molecular　dynamics　(ReaxFF　MD)　simulation,　as　well　as　mineral　aggregate　molecular　systems.　The　oxidized　models　for　each　asphalt　molecule　were　proposed,　which　closely　matched　actual　experimental　study　results.　The　simulation　results　showed　that　sulfur　atoms　oxidized　the　fastest,　followed　by　benzyl　carbon.　As　the　degree　of　oxidation　increased,　the　viscosity　and　glass　transition　temperature　of　asphalt　molecules　also　increased.　The　interfacial　energies　of　various　systems　were　analysed,　such　as　foamed　asphalt-aged　asphalt,　asphalt-aggregate　and　asphalt-recycled　aggregate.　It　was　found　that　the　adhesion　of　asphalt-aged　asphalt　decreased　due　to　the　presence　of　water,　but　this　phenomenon　was　not　observed　in　the　asphalt-recycled　aggregate　interface　when　the　water　content　was　less　than　2%.　The　mean　square　displacement　results　showed　that　3%　or　less　water　content　facilitated　the　diffusion　and　movement　of　molecules　in　asphalt-recycled　aggregate　systems,　whereas,　in　asphalt-aggregate　systems,　only　1%　water　content　was　sufficient.　©　2025　The　Author(s).