Cement-based　materials　inherently　face　a　conflict　between　load-bearing　capacity　and　fire　resistance.　To　address　this　issue,　combined　using　several　types　of　concrete　has　the　potential　to　improve　both　mechanical　and　fire　performance.　Therefore,　this　paper　focuses　on　the　composite　concrete　structures,　particularly　the　fire　performance　of　those　incorporating　recycled　aggregate　concrete　(RAC),　and　explores　their　future　development.　This　study　considers　three　main　aspects:　the　properties　of　RAC,　composite　concrete　structures,　and　the　concrete-concrete　interface.　The　findings　indicate　that　RAC　exhibits　excellent　fire-insulation　properties　due　to　its　lower　thermal　conductivity.　The　use　of　RAC　in　composite　concrete　structures　can　effectively　enhance　fire　resistance　while　having　a　limited　impact　on　mechanics.　The　bonding　properties　of　discontinuous　concrete-concrete　interface　in　composite　concrete　structures　significantly　decreases　when　exposed　to　elevated　temperatures,　which　may　adversely　affect　structural　integrity　and　requires　attention.　In　summary,　this　paper　provides　a　comprehensive　understanding　of　the　thermal　insulation　properties　of　RAC,　thereby　promoting　its　application　in　composite　concrete　structures　and　offering　a　viable　approach　to　enhancing　the　fire　resistance　of　concrete　structures.　©　2025　Elsevier　Ltd