Compressive behavior of GFRP tube filled with structural polypropylene fiber reinforced seawater coral aggregates concrete

Abstract

To address the challenge of shortage of concrete raw materials in the construction of reefs and islands, a novel composite column of GFRP tube filled with structural polypropylene fiber reinforced seawater coral aggregates concrete (SPFSCAC) is proposed, which not only utilizes local marine resources but also resists chloride corrosion in marine environment. The compressive behavior of SPFSCAC filled GFRP tube was investigated taking the effects of GFRP tube thickness and SPF content into account. The experimental results indicated that the usage of coral aggregates reduced the compressive performance of SCAC filled GFRP tube. After adding SPF, the compressive bearing capacity and corresponding strain of SPFSCAC filled GFRP tube were increased by 10.9 ∼ 26.9% and 11.9 ∼ 24.2% respectively compared to SCAC filled GFRP tube having an identical GFRP tube thickness, and would increase as increasing the SPF content. Adding SPF can eliminate the performance defects caused by the use of coral aggregates and enhance the core concrete. Under axial compression, the load–strain curves of SPFSCAC filled GFRP tube showed clearly four-stage characteristics. According to the transition points of experimentally obtained load–strain curves, the load–strain relationship model for SPFSCAC filled GFRP tube was proposed, and the reliability of the load–strain relationship model was verified through deviation analysis, thus providing a reference for the design and application of this new SPFSCAC filled GFRP tube.