Incorporating　form　stable　phase　change　material　(FSPCM)　can　enhance　the　thermal　storage　capacity　of　concrete.　However,　it　often　reduces　the　mechanical　properties　of　concrete.　In　this　study,　we　developed　an　aluminum　encapsulated　octadecane　composite　aggregate.　The　research　objective　is　to　enhance　both　the　mechanical　and　thermal　properties　of　energy　storage　concrete　simultaneously.　The　results　indicate　that　the　compressive　strength　of　energy　storage　concrete　decreases　with　higher　aluminum　aggregate　content　and　smaller　diameters,　while　the　splitting　strength　increases.　Aluminum　aggregate　enhances　the　ductility　and　thermal　conductivity　of　energy　storage　concrete,　with　conductivity　increasing　proportionally　to　aluminum　content　but　remaining　unaffected　by　aggregate　diameter.　When　the　volume　fraction　of　FSPCM　is　identical,　the　aluminum　aggregate　energy　storage　concrete　exhibits　moderate　compressive　strength　but　higher　latent　heat　capacity.　In　addition,　thermal　energy　storage　performance　tests　indicate　that　the　aluminum　aggregate　energy　storage　concrete　can　reduce　the　heat　load　of　the　test　unit　by　approximately　30–40　%.　These　developed　products　have　the　potential　for　application　in　phase　change　energy　storage　buildings.　©　2025　Elsevier　Ltd