Disadvantages　of　the　lap-spliced　rebar　connection　between　SC　composite　wall　and　RC　foundation　include　long　lap-splicing　length,　complicated　construction,　rebar　congestion,　and　difficulty　in　maintaining　vertical　straightness.　In　order　to　solve　the　listed　limitations,　an　innovative　connection　was　proposed　which　used　steel　tube　instead　of　rebars　to　optimize　the　structural　behavior　of　the　wall,　and　to　improve　construction　efficiency.　This　paper　conducted　axial　tensile　tests　on　five　connections　and　the　effects　of　diameter-to-thickness　ratio,　number　of　tie　bar,　and　steel　ratio　on　the　axial　tensile　behavior,　crack　distribution,　axial　tensile　strength,　and　tensile　stiffness　were　studied.　The　test　results　showed　that　the　core　concrete　exhibited　bottom　diagonal　cracks,　middle　diagonal　cracks,　and　upper　splitting　cracks.　Increasing　the　diameter-to-thickness　ratio　of　the　tube　was　beneficial　for　improving　the　compatibility　between　steel　and　concrete,　thereby　increasing　the　axial　tensile　strength　and　tensile　stiffness.　Tie　bars　were　able　to　mitigate　the　splitting　cracks,　maintain　integrity　of　the　specimen,　reduce　the　eccentricity,　and　improve　axial　tensile　performance.　The　distribution　of　deformation　during　axial　tension　was　uneven,　showing　a　pattern　that　the　most　deformation　accumulated　at　the　upper　and　lower　ends,　while　the　deformation　at　the　middle　was　small.　　©　The　Author(s),　under　exclusive　license　to　Springer　Nature　Singapore　Pte　Ltd.　2025.