Long-term performance of Basalt FRP reinforced marine geopolymer concrete in harsh environment

The current study reports on the long-term structural performance of novel reinforced marine geopolymer concrete beams under accelerated weathering conditions. The study covers the flexural performance of 40 geopolymer concrete beams reinforced with BFRP (Basalt Fibre Reinforced Polymer) bars, including 12 beams under sustained loading when exposed to 3, 6 and 12 months of accelerated marine environment consisting of tidal cycles of seawater at a temperature of 50 degrees C. The experimental results revealed that the novel marine geopolymer concrete reinforced with BFRP bars reported minimal micro and macro-mechanical degradation compared to geopolymer concrete or ordinary concrete beams under the same exposure environment, with and without sustained loading. The BFRP-reinforced SCGC (Self-Compacting Geopolymer Concrete) beams reported 87% residual ultimate load after 12 months of exposure to marine environments, while the sustained loaded BFRP-SCGC (Basalt Fibre Reinforced Polymer-Self-Compacting Geopolymer Concrete) beams reported a residual strength of 79%. In addition, microstructural assessment using SEM (Scanning Electron Microscopy) and EDS (Energy Dispersive X-ray Spectroscopy) analysis revealed that after 12-month exposure, there was a trace of chloride salts indicating the chemical ingress over time; however, the impact on structural properties is not distinct.