This　work　proposes　to　ameliorate　the　performance　of　recycled　aggregate　concrete　(RAC)　by　enhancing　the　interfacial　transition　zone　(ITZ).　In　light　of　this,　the　recycled　aggregate　was　pre-treated　by　the　sulfoaluminate　cement　(SAC)　slurry　and　water　glass　(WG)　solution　at　varying　water-to-SAC　(w/s)　ratios　and　WG　concentrations,　respectively.　The　optimum　modification　efficiency　was　observed　at　a　w/s　ratio　of　0.8　and　a　WG　concentration　of　3　wt%.　It　was　found　that　the　SAC-treatment　of　RA　led　to　a　layered,　sandwich-shaped　new　ITZ　which　presented　an　overall　higher　microhardness　compared　to　the　normal　ITZ　in　the　reference　RAC.　The　WG-treatment　enhanced　both　the　new　and　old　ITZ　but　its　modification　on　RAC＇s　mechanical/durability　performance　was　less　stable　than　the　SAC-treatment.　The　SAC　treatment　is　thereby　suggested　to　be　more　appropriate　for　RAC＇s　modification　in　practical　use,　also　considering　its　lower　risk　of　alkali-silica　reaction　than　the　WG　treatment.　©　2021　Elsevier　Ltd