Structural response of aluminium alloy concrete filled tubular columns

There is an increasing trend of using structural aluminium within the construction industry, due to its superior mechanical properties, such as high strength-to-weight ratio and high resistance to corrosion. The use of aluminium combined with concrete can be advantageous in terms of the resultant structural capacity. Currently, the design standards for the structural use of aluminium are substantially conservative and less exhaustive, which limits the full exploitation of aluminium as a structural material. This paper aims at developing more reliable structural design specifications based on experimental testing of aluminium-concrete composite columns. A series of specimens comprising concrete-filled aluminium hollow sections were experimentally investigated. Square hollow sections and rectangular hollow sections with different aspect ratios were considered. The hollow sections employed 6082-T6 aluminium alloy and were filled with concrete of C30 grade. The specimens were subjected to gradually increasing axial compressive loading until their failure. The behaviour of the specimens was observed through continuous monitoring and recording of the strain and displacement through instrumentation mounted on the specimens at critical locations. The experimentally obtained load capacities were compared to those predicted by European design specifications. Conclusions with regards to the structural efficiency of concrete-filled aluminium alloy columns are drawn and design recommendations in line with the observed structural response are made.