Title: Axial Load-Bending Moment (P-M) Interaction of Geopolymer Fiber-Reinforced Concrete Slender Columns Reinforced with Steel, Glass Fiber-Reinforced Polymer, or Hybrid Double Layer

Author(s): Mohammad AlHamaydeh and Fouad Amin

Publication: Structural Journal

Volume: 121

Issue: 4

Appears on pages(s): 63-73

Keywords: fiber-reinforced concrete (FRC); geopolymer concrete (GPC); glass fiber-reinforced polymer (GFRP) reinforcing bar; hybrid reinforcement; interaction diagrams; slender columns; slenderness ratio.

DOI: 10.14359/51740570

Date: 7/1/2024

Abstract:
A numerical integration model is developed to investigate the axialload-bending moment interactions of fiber-reinforced geopolymerconcrete (FRGPC) columns reinforced with double layers of steel,glass fiber-reinforced polymer (GFRP), or hybrid reinforcement.The model accounts for material and geometric nonlinearities,including the slenderness-induced second-order effects through aniterative layer-by-layer integration scheme of the critical section.Analytical investigations were conducted for various double-layerreinforcement configurations of steel, GFRP, and hybrid reinforcement. The effect of adding steel/synthetic macrofibers to the concrete matrix was also investigated. Moreover, comprehensivedeterministic sensitivity analyses were conducted to assess theinfluence of the concrete compressive strength (fco), reinforcementfiber dosage, and the longitudinal/transverse reinforcementratios on different response values. For the axial load capacity ofGFRP-reinforced columns, the longitudinal reinforcement ratiowas found to be the most influential parameter, whereas for thesteel/hybrid reinforced columns, fco was the most influential parameter. Moreover, for all the simulated configurations, confinement efficiency was most sensitive to fco out of all the investigated parameters. The longitudinal reinforcement ratio most influenced the bending moment capacity and the associated secant stiffness. Lastly, axial load-bending moment interactions were developed for various reinforcement configurations. The interactions included the effects of the slenderness ratio, the macrofiber type, longitudinal/transverse reinforcement type/strength, and the longitudinal reinforcement ratio. The GFRP-reinforced columns showed more sensitivity to slenderness effects than steel-reinforced columns.