Evaluation of bond performance of glass fiber rebars embedded in sustainable concrete

Abstract

This paper presents experimental and statistical investigations of the bond performance of sand-coated glass fiber rebars (GFRP) embedded in three types of concrete. The need for corrosion-free materials has become more wanted to avoid the high-cost of corrosion repairs. Glass fiber is a strong candidate to replace steel reinforcement in concrete structures due to its cost-effectiveness and great corrosion resistance. On the other hand, the production of cement generates substantial amount of carbon dioxide, therefore other alternatives are in high demand. Fly ash is considered one of these alternatives used to fully or partially replace cement in concrete to avoid the problem of carbon dioxide emission. In this study, other than conventional concrete (CC), 50% and 70% replacement of cement with fly ash were implemented as two types of high-volume fly ash concrete (HVFAC). Twenty-four cylindrical specimens were pullout-tested following the Réunion Internationale des Laboratoires et Experts des Matériaux, systèmes de construction et ouvrages (RILEM) recommendations. The parameters evaluated in this study were: rebar type, rebar diameter, and concrete type. In addition to the experimental work, statistical analyses were conducted including predictions of GFRP’s bond strength, peak toughness, and post-peak toughness. Test results showed that, despite the type of concrete used, peak bond strengths of GFRP rebars were lower than those of mild steel, but the post-peak strength were higher in GFRP bars. In addition, GFRP rebars were microstructurally and chemically examined, and there were no visual signs of any microstructural and chemical attack resulted from the fly ash-based concrete.