Concrete-filled aluminum circular hollow section column tests

An experimental investigation of concrete-filled aluminum circular hollow section (CHS) stub columns is presented in this paper. A series of tests was conducted to investigate the effects of the geometric dimension of the aluminum CHS and concrete strength on the behavior and strength of concrete-filled aluminum CHS stub columns. The structural performance of the concrete-filled aluminum CHS stub columns was investigated using different concrete cylinder strengths of 40, 70 and 100 MPa. The CHS tubes were fabricated by extrusion using 6061-T6 heat-treated aluminum alloy having nominal 0.2% proof stress of 240 MPa. The diameter-to-thickness ratio of the CHS tubes ranged from 9.7 to 59.7. The column lengths were chosen so that the length-to-diameter ratio generally remained at a constant value of 3 to prevent overall column buckling. The concrete-filled aluminum CHS specimens were subjected to uniform axial compression. The column strengths, load-axial shortening relationship, load-axial strain relationship and failure modes of columns were presented. The test strengths were compared with the design strengths calculated using the American specifications and Australian/New Zealand standards for aluminum and concrete structures. It is shown that the design strengths are generally conservative for concrete-filled aluminum CHS stub columns.