Study on Durability and Compression Behaviors of BFRP Bars under Seawater Deterioration and Constraint Condition

Abstract

The microstructural characterization of Basalt Fiber Reinforced Polymer (BFRP) bars under seawater deterioration (dry–wet cycles modes and immersion modes) was performed by scanning electron microscopy (SEM) and X-ray energy spectrum analyzer (EDS). Then, uniaxial compressive tests were carried out on the corroded BFRP bars to explore the effects of different corrosion periods, diameters, and slenderness ratios on the degradation of compressive performance and durability in seawater corrosion and constraint condition. The results showed that dry–wet cycles of seawater caused patchy pitting on the surfaces of BFRP bar, and white granular foams adhered to the bar surface after seawater immersion. The internal microstructure of BFRP bar was deteriorated, and the bonding force between the fiber and resin was reduced with the increase of dry–wet cycles. Five failure modes of BFRP bars occurred in uniaxial compressive tests, namely crushing failure, transverse cracking failure, shearing failure, splitting failure, and buckling failure. The increase of corrosion cycles significantly decreased the bearing capacity and compressive strength, but had little effect on the compressive elastic modulus of BFRP bars. The dry–wet cycles of seawater was more harmful to the mechanical properties of BFRP bars than immersion corrosion. Meanwhile, the mechanical properties of BFRP bars were affected by their diameters and slenderness ratios to some extent.