Performance of RC double skin tubular column confined with UPVC pipe under axial compression

Concrete-Filled Double Skin Tubular (CFDST) compression members have a good prospect in the construction sector of bridges and buildings due to the confinement effect and that’s why it has become a significant research drive throughout the last few decades. With an aim to study the behavior of reinforced CFDST stub columns, under the effect of monotonic axial compressive load, a detailed investigation has been carried out. Unplasticized Poly Vinyl Chloride (UPVC) pipe has been used as an unusual, but easily available confinement material to keep the structural member safe from aggressive and environmental hazards as well. 72 cylindrical specimens 200 mm and 90 mm in diameter, respectively, for the outer and inner confining pipes, consisting of both unconfined and UPVC confined specimens having heights 500 mm and 750 mm were tested with three different pipe thicknesses and three different concrete grades of M20, M25 and M30, as the infill core material. An evaluation of the maximum load-carrying capability has been done using different existing codes of practice and literature, and a generalized equation has been proposed for the purpose, which is in agreement with the findings of the experimental outcomes.