Rapid　freezing-thawing　tests　of　concrete　were　conducted　in　laboratory　after　different　carbonation　times.　The　mechanical　properties　and　microscopic　pore　characteristic　parameters　were　investigated,　and　the　concept　of　＇pore　sinuosity＇　of　concrete　was　put　forward.　The　test　results　indicate　that　carbonation　contributes　to　enhance　frost　resistance　of　concrete,　the　314　days＇　carbonation　can　make　dynamic　elastic　modulus　of　concrete　reduce　at　least　3%12%　due　to　freezing-thawing　cycles.　Carbonation　increases　pore　sinuosity　of　concrete.　Moreover,　fly　ash　can　also　enlarge　pore　sinuosity　of　concrete,　and　erosion　medium＇s　seepage　path　becomes　longer,　thus　the　frost　resistance　of　concrete　is　enhanced.　The　correlation　between　air-entraining　and　pore　sinuosity　of　concrete　is　loose,　which　shows　that　the　mechanism　of　frost　resistance　affected　by　air-entraining　and　mineral　admixture　for　concrete　is　different.　©　2017,　Editorial　Department　of　Journal　of　Building　Materials.　All　right　reserved.