Axial Strengths of Concrete Stub Columns Filled with Demolished Concrete Segments/Lumps

The issue on disposing of waste concrete continues to cause concern worldwide. In order to promote the reuse or recycling of demolished concrete at a structural-grade level, two kinds of innovative concrete columns, namely, reinforced concrete (RC) column and concrete filled steel tubular (CFST) column incorporating demolished concrete lumps (DCLs) or demolished concrete segments (DCSs) were proposed earlier. For the purpose of investigating the axial strengths of these two kinds of columns, eight RC stub columns (including two RC stub columns filled with DCLs, four RC stub columns filled with DCSs and two conventional RC stub columns) and two CFST stub columns filled with DCLs were tested respectively under quasi-static axial loading through two experimental programs. Test results of the two experimental programs are presented herein in detail, and the effectiveness of current design provisions for calculating the axial strengths of each kind of column is discussed.