Structural Behaviour of Slender PVC Composite Columns Filled with Concrete

In this study, the performance of slender PVC-concrete columns was investigated using variables including concrete filling compressive strength, column slenderness ratio, and PVC section compactness ratio. The specimens were subjected to uniaxial compression in two loading modes; in the first mode, a PVC tube was utilised to enhance the concrete core as a composite element, and in the second mode, a PVC tube was utilised to confine the concrete core only. Nine PVC-concrete sections with different polyvinyl chloride tube characteristics and different filled concrete compressive strengths were considered in several fabricated slender PVC-concrete columns. The column lengths were varied so that overall column buckling could be investigated. The results showed that the composite mode columns exhibited more strength improvement than those in confined mode. Experimentally predicated effective flexural stiffness was thus normalised in terms of filling concrete stiffness and PVC tube stiffness, and the normalised results indicated that effective flexural stiffness depends on the mode (confining or composite), PVC and filling concrete strength, and column slenderness ratio.