Study of concrete-filled unplasticized poly-vinyl chloride tubes in marine environment

Abstract

This article presents an experimental study on columns prepared by filling reinforced concrete in unplasticized poly-vinyl chloride tubes exposed to artificial sea water prepared in the laboratory. Totally, 72 reinforced concrete-filled unplasticized poly-vinyl chloride tubular column specimens of length 800 mm were cast by filling the reinforced concrete in unplasticized poly-vinyl chloride tubes having 160, 200 and 225 mm diameters. The diameter-to-thickness ratio and length-to-diameter ratio of the specimens vary from 22.48 to 40.14 and 3.56 to 5, respectively. Out of 72 specimens, 36 specimens were converted to bare reinforced concrete columns by removing unplasticized poly-vinyl chloride tubes. In total, 18 reinforced concrete–filled unplasticized poly-vinyl chloride tubular and 18 bare reinforced concrete specimens were kept completely submerged in artificial sea water of salt concentration 20N for the period of 6 months while 36 specimens of reinforced concrete–filled unplasticized poly-vinyl chloride tubular were kept for 28 days after covering the top and bottom of specimens with thick polyethylene sheet to avoid evaporation of water. Out of these 36 reinforced concrete–filled unplasticized poly-vinyl chloride tubular specimens, 18 specimens were converted to bare specimens at the time of testing. All the specimens were tested by applying axial load on concrete core only to obtain load–displacement curves and modes of failure. No degradation in the strength and ductility of reinforced concrete–filled unplasticized poly-vinyl chloride tubular specimens was observed after submergence in sea water. It can be concluded that unplasticized poly-vinyl chloride tube provides a safety jacket to encased concrete core, and as a result improve strength, ductility.