In　this　study,　combined　waste-derived　alkali　activators　are　used　to　prepare　volcanic　ash-based　geopolymers　and　to　evaluate　their　durability　under　freeze–thaw　conditions.　The　comparable　alkali　activators　are　Na2SO4–Ca(OH)2　(N–C),　Na2SO4-calcium　carbide　residue　(N-CCR),　Na2SO4-calcium　carbide　residue-NaOH　(N-CCR-H),　Na2SO4-calcium　carbide　residue-Na2SiO3　(N-CCR-S).　Microstructure　and　strength　of　the　geopolymers　are　characterized　through　XRD,　SEM,　FTIR,　NMR　and　compressive　strength　measurements.　Pore　structure　of　the　geopolymers　is　determined　by　adsorption/desorption　isotherms　and　BET　calculations.　It　is　found　that　the　ternary　alkali　activators　give　superior　activation　synergy　than　dual　alkali　activators.　The　compressive　strengths　of　N-CCR-S　and　N-CCR　geopolymers　are　61.0　MPa　and　23.1　MPa　after　7　d　in　air.　After　freeze–thaw　cycles　for　30　days,　the　compressive　strength　of　the　N-CCR-S　geopolymer　is　three　times　higher　than　that　of　the　N-CCR　geopolymer.　These　significant　differences　originate　from　their　N-A-S-H　and　C-(A)-S-H　gel　structures.　The　N-CCR-S　geopolymers　possess　a　more　homogeneous　and　dense　microstructure　with　low　pore　structure.　This　study　proposes　a　method　for　the　effective　utilization　of　volcanic　ash　and　alkaline　solid　wastes.　©　2022　Elsevier　Ltd