CHARACTERISTIC STUDY ON CONCRETE STEEL DOUBLE SKINNED TUBES AND CONCRETE FILLED STEEL TUBES UNDER AXIAL COMPRESSIVE STRENGTH

The present work aims at a comparative study on the axial compressive strength of concrete filled steel tubes and concrete filled double skinned steel tubes with both inner and outer tubes filled with concrete and the variation of compressive strength is studied keeping the area of steel and concrete used as constant for both the cases. The impact of the variation of inner and outer steel tube thickness towards compressive strength is also studied and the stress-strain relationships are recorded. The specimens are also modelled in finite element software ASNYS workbench 16.0 and the obtained results were in accordance with the experimental results. It was found that concrete steel double skinned steel tubes of outer tube thickness higher than inner tube thickness showed an increase in load carrying capacity whereas the concrete steel double skinned tubes of inner tube thickness higher than outer tube thickness showed a reduction in axial compressive strength when compared with concrete. The concrete steel double skinned steel tubes showed an enhancement in ductility thus it is more favorable to use double skinned steel tubes for construction as it prevents sudden failure and can give indications prior to failure.