This　paper　describes　a　series　of　tests　on　steel　tubular　columns　of　circular　and　square　section　filled　with　normal　concrete　and　recycled　aggregate　concrete.　Thirty　specimens,　including　24　recycled　aggregate　concrete　filled　steel　tubular　(RACFST)　columns　and　6　normal　concrete　filled　steel　tubular　(CFST)　columns,　were　tested　to　investigate　the　influence　of　variations　in　the　tube　shape,　circular　or　square,　concrete　type,　normal　concrete　and　recycled　aggregate　concrete,　and　load　eccentricity　ratio,　from　0　to　0.53　on　the　performance　of　such　composite　columns.　The　test　results　show　that　both　types　of　filled　columns　failed　due　to　overall　buckling.　Comparisons　are　made　with　predicted　ultimate　strengths　of　RACFST　columns　using　the　existing　codes,　such　as　ACI　318-1999,　AIJ-1997,　AISC-LRFD-1999,　BS5400-1979,　DBJ13-51-2003　and　EC4-1994.　A　theoretical　model　for　normal　CFST　columns　is　adopted　in　this　paper　for　RACFST　columns.　The　predicted　load　versus　deformation　relationships　are　in　good　agreement　with　test　results.　(c)　2006　Elsevier　Ltd.　All　rights　reserved.