Structural Behavior of Concrete Columns Reinforced with BFRP Bars: Experimental Study and Predictive Models

Abstract

In recent years, research has explored using glass fiber-reinforced polymer (GFRP) bars as a corrosion-resistant alternative to steel reinforcement in concrete columns. Design guidelines have been established in ACI 440.11–22 for GFRP bars. However, there's currently no specific code for Basalt fiber-reinforced polymer (BFRP) bars in concrete columns due to limited experimental data. This study investigates using BFRP bars and ties as an alternative to steel reinforcement in concrete columns. It presents results from testing 11 columns under concentric loads. The test variables included the longitudinal BFRP reinforcement ratio, BFRP tie spacings, BFRP tie diameter, and reinforcement type. The experimental results showed a resemblance in the performance of concrete columns reinforced with BFRP and steel bars. Longitudinal BFRP bars contributed between 6.4 and 17.2% to the ultimate load-carrying capacity. A reduction in tie spacing was observed to slightly improve the load-carrying capacity. Moreover, when using the same volumetric reinforcement ratio, employing smaller diameter bars with closer spacings proved to be more efficient than using larger diameter bars with greater spacings. The study also introduced two models for predicting the maximum load capacity of BFRP-reinforced concrete columns, and the proposed models showed high accuracy compared to existing models in the literature.