Pore　structure　is　one　of　the　major　characteristics　influencing　the　freeze-thaw　resistance　of　concrete.　Although　the　air-void　spacing　factor　associated　to　the　porosity　features　of　concrete　is　known　as　a　widely　used　parameter　to　assess　the　freeze-thaw　resistance,　controversies　on　the　determination　of　critical　values　of　air-void　spacing　factor　still　exist　in　many　related　studies.　Moreover,　it　is　reported　that　the　pore-size　distribution　in　concrete　also　significantly　affects　its　freeze-thaw　resistance.　In　this　study,　a　fractal　model　was　established　to　characterize　the　air　voids　size-distribution　in　concrete,　and　the　corresponding　fractal　dimension　obtained　from　the　fractal　model　was　validated　for　its　effectiveness　in　describing　the　air　voids　size-distribution　quantitatively.　By　comparison　to　a　fractal　model　presented　in　a　previous　study,　the　fractal　model　proposed　in　this　study　was　found　more　reasonable　and　reliable.　Based　on　the　theoretical　principle,　correlations　between　air　voids　size-distributions　and　the　measured　freeze-thaw　resistances　of　concrete　were　established　through　laboratory　experiments.　The　results　revealed　that　air　voids　size-distribution　exhibited　more　significant　influence　on　the　freeze-thaw　resistance　of　concrete　than　the　air-void　spacing.　Furthermore,　a　regression　equation　with　fairly　high　correlation　coefficient　between　the　fractal　dimension　of　air　voids　size-distribution　and　the　durability　factors　of　concrete　was　obtained　from　the　results.　©　2013　Elsevier　Ltd.　All　rights　reserved.