Structural Behavior of GFRP-Reinforced Circular HFRC Columns Under Concentric and Eccentric Loading

摘要

The previous research is rich in plain concrete columns reinforced with glass fiber-reinforced polymer (GFRP) bars, but it isdeficient in GFRP-reinforced concrete columns incorporating hybrid fibers. The present study aims to explore and comparethe structural behavior of steel and GFRP-reinforced concrete columns having hybrid fibers (SHFC and GHFC columns). Twotypes of fibers, i.e. steel fibers and polypropylene fibers, were used to develop the hybrid fiber-reinforced concrete. A total of18 circular concrete columns (9 SHFC columns and 9 GHFC columns) having a height of 1150 mm and a diameter of 250 mmwere constructed and tested under axial loading at various eccentricities. The test measurements portrayed that the SHFCcolumns presented a better performance in terms of axial strength (about 20% higher) and ultimate deflections. The GHFCcolumns presented higher ductility indices compared with SHFC columns. Both steel and GHFC columns showed similarfailure modes and similar reductions in the axial strength when subjected to eccentricities. The newly developed empiricalmodel for the prediction of the axial strength of GHFC columns showed a close agreement with the experimentation. Thus,the comparative study solidly substantiates the application of the proposed empirical model.