This　research　aims　to　quantify　the　degree　of　blending　(DoB)　between　virgin　and　aged　asphalt　binders　in　recycled　asphalt　mixture　during　construction　stage　by　using　the　Confocal　Laser　Scanning　Microscopy　(CLSM)　technology.　In　this　research,　virgin　SBS-modified　binder　was　employed　as　a　tracer.　Wood　cube　aggregate　was　used　as　RAP　aggregate　to　be　distinguished　from　the　asphalt　mixtures.　Various　heating　temperature　and　storage　time　conditions　were　set　up　for　laboratory-produced　recycled　asphalt　mixtures　to　simulate　different　construction　stages,　including　storage,　transportation,　laying,　and　compaction　processes.　The　CLSM　was　utilized　to　detect　fluorescence　concentration　diffusion　of　virgin　SBS-modified　binder　on　the　simulated　RAP　aggregate　samples　at　each　construction　stage.　A　method　for　quantifying　the　DoB　of　virgin　and　aged　asphalt　binders　was　proposed.　Results　demonstrated　that　the　simulated　construction　stages　have　significant　impacts　on　blending　efficiency　of　virgin　and　aged　asphalt　binders.　After　mixing　process,　the　DoB　of　tested　binders　was　found　to　be　43.4　%.　The　DoB　values　increased　19.7–31.6　%　during　storage　stage　range,　and　7.2–9.2　%　during　transport　stage.　The　DoB　values　only　increased　2–4　%　during　laying　and　compaction　stage.　The　overall　increase　of　the　DoB　can　be　as　high　as　30　%,　indicating　that　settings　of　construction　stages　are　crucial　for　the　blending　of　virgin　and　aged　asphalt　binders　in　recycled　asphalt　mixtures.　©　2025　Elsevier　Ltd