Three　concrete　mixes　with　different　water-to-binder　ratios　and　dosages　of　cement　replacement　materials　(fly　ash　and　slag　powder)　were　exposed　to　alternate　carbonation　and　freezing–thawing　actions.　The　compressive　strength,　dynamic　elastic　modulus　and　mass　of　all　specimens　were　measured　and　analyzed,　also　compared　to　the　results　obtained　from　the　carbonation-only　and　freezing–thawing-only　cases.　Test　data　show　that　the　relative　compressive　strength,　the　relative　dynamic　elastic　modulus　and　the　mass　of　concrete　specimens　exposed　to　carbonation-only　cases　increase　with　the　carbonation　time　due　to　sufficient　carbonation　reaction,　whereas　they　decrease　with　the　corresponding　testing　time　whenever　they　are　exposed　to　freezing–thawing-only　cases　or　alternate　regimes.　Additionally,　under　the　same　freezing–thawing　numbers,　the　concrete　specimens　exposed　to　alternate　regimes　have　slightly　higher　relative　compressive　strength,　lower　relative　dynamic　elastic　modulus　and　larger　mass　loss　than　that　exposed　to　freezing–thawing-only　cases.　Based　on　the　obtained　dynamic　elastic　modulus　from　the　above　different　environmental　cases,　a　damage　mechanics　fitting　model　of　concrete　considering　alternate　carbonation　and　freezing–thawing　actions　were　established　with　high　reliability.　©　2022,　The　Author(s),　under　exclusive　license　to　Springer　Nature　Singapore　Pte　Ltd.