Finite element modelling of load-carrying capacity of concrete-filled unplasticised polyvinyl chloride (UPVC) tubes exposed to marine environment

Abstract

ABSTRACT This paper presents a Finite element modelling of the compression process of columns prepared by filling reinforced concrete (R.C.) in unplasticised polyvinyl chloride (UPVC) tubes and exposed to artificial seawater. Total 36 reinforced concrete-filled UPVC tubular (RCFUT) column specimens of length 800 mm are used for modelling. The UPVC tubes having 160, 200 and 225 mm diameters are used as a tube. Along with the RCFUT columns bare RCC columns of identical geometries were also modelled to compare the load-carrying capacity and associated mode of deformation. A few specimens were also tested to find material parameters after keeping them completely submerged in artificial sea water of salt concentration 20 N for a period of six months. Material modelling of UPVC tube was done before exposure to sea water and after exposure to seawater for six months in 20 N solution. The comparison of results shows that degradation in strength and ductility was marginal. The finite element model is validated by comparing the load-displacement curves and modes of failure of tested specimens with simulated ones. It was found that strength and energy absorption of RCFUT specimens were 1.2–1.37 and 2.06–4.03 times that of bare R.C. specimens. It can be concluded that the UPVC tube provides a safety jacket to the encased concrete core and as a result improvement in strength, ductility and energy absorption capacity can be achieved. Finite element simulation can be used as an alternative to physical testing if material parameters are obtained with precision.