Durability assessment of GFRP rebars in marine environments. (25th April 2022)

• Record Type: Journal Article
• Authors: Ruiz Emparanza, Alvaro; Kampmann, Raphael; De Caso, Francisco; Morales, Carlos; Nanni, Antonio
• Is Part Of: Construction & building materials. Volume 329(2022)
• Publication Date: 2022-04-25
• Subjects: Composite FRP rebar -- Durability -- Service life -- Marine structures -- Reinforced concrete; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2022.127028
• Languages: English
• ISSNs: 0950-0618

Abstract

Abstract: Technologies developed over the last two decades have facilitated the use of glass fiber reinforced polymer (GFRP) bars as internal reinforcement for concrete structures, specially in coastal environments, mainly due to their corrosion resistance. To-date, most durability studies have focused on a single mechanical parameter (tensile strength) and a single aging environment (exposure to high alkalinity). However, knowledge gaps exists in understanding how other mechanical parameters and relevant conditioning environments may affect the durability of GFRP bars. To this end, this study assesses the durability for different physio-mechanical properties of GFRP rebars, post exposure to accelerated conditioning in seawater. Six different GFRP rebar types were submerged in seawater tanks, at various temperatures (23 °C, 40 °C and 60 °C) for different time periods (60, 120, 210 and 365 days). In total six different physio-mechanical properties were assessed, including: tensile strength, E-modulus, transverse and horizontal shear strength, micro-structural composition and lastly, bond strength. It was inferred that rebars with high moisture absorption resulted in poor durability, in that it affected mainly the tensile strength. Based on the Arrhenius model, at 23 °C all the rebars that met the acceptance criteria by ASTM D7957 are expected to retain 85 % of the tensile strength capacity. Highlights: Six GFRP rebar types were exposed to natural seawater for one year. Six physio-mechanical properties and three exposure temperatures were evaluated. The GFRP rebar durability appears to be proportional to the moisture absorption . The Arrhenius model was only successfully applied for tensile retention values. The currently accepted CE value of 0.7 appears to be too conservative.