The　layer-by-layer　stacking　process　of　3D　Printing　Construction　Technology　(3DPCT)　inevitably　leads　to　weak　bonding　areas　between　the　interlayer　interfaces　and　the　interstrip　interfaces,　which　affect　the　mechanical　properties　of　the　printed　structure.　The　effects　of　different　carbonation　time　of　recycled　sand　on　the　mechanical　properties　and　interfacial　bonding　performance　of　3D　printed　cement-based　material　with　a　100　%　replacement　rate　of　carbonated　recycled　sand　(3DPCRS)　were　explored.　Although,　the　carbonation　time　of　recycled　sand　affected　the　mechanical　anisotropy　of　the　printed　specimens,　the　carbonation　treatment　of　recycled　sand　cannot　eliminate　the　mechanical　anisotropy　of　3D　printed　specimens.　With　the　extension　of　the　carbonation　time　of　recycled　sand,　the　interfacial　bonding　performance　was　gradually　improved.　At　28　days,　the　interlayer　shear　strength　and　interstrip　shear　strength　of　T7　group　increased　by　21.5　%　and　18.7　%,　respectively.　After　the　carbonation　of　recycled　sand,　the　indentation　modulus　of　the　interlayer　interface　was　increased　with　the　decrease　of　interface　width　and　porosity,　which　improved　the　pore　structure　and　the　mechanical　properties　of　the　printed　specimens.　©　2024　Elsevier　Ltd