# Axial Compression of BFRP Spiral Strip–PVC Tube Confined Fiber-Recycled Concrete: Experiment and FEM Analysis

## TL;DR

This study explores using BFRP spiral strips and PVC tubes to reinforce recycled concrete under compression, showing improved strength and practical benefits.

## Contribution

The study introduces BFRP spiral strips as a more effective and easier-to-install alternative to circumferential strips for concrete reinforcement.

## Key findings

- BFRP spiral strips significantly enhance the load-bearing capacity and ductility of RAC cylinders.
- The winding angle and spacing of BFRP strips have a major impact on structural performance.
- The developed strength model shows less than 10% average error when compared to experimental results.

## Abstract

The use of short cylinders of recycled aggregate concrete (RAC) reinforced with basalt fiber-reinforced polymer (BFRP) circumferential strips and polyvinyl chloride (PVC) tubes has been proven effective in previous studies. However, BFRP circumferential strips are cumbersome to install and do not ensure the integrity of the BFRP strips. Therefore, this study investigates axial compression experiments on RAC short cylinders reinforced with BFRP spiral strips and PVC tubes. A combination of experimental studies, finite element simulations, and theoretical analyses revealed that the winding angle and spacing of BFRP strips significantly affect the load-bearing capacity and ductility of the restrained specimens. Additionally, an improved strength model was developed based on an existing model. When evaluated using both computational and experimental results, the equations generated in this study showed an average error of less than 10%. The findings indicate that the composite structure provides effective reinforcement and offers valuable reference information for practical applications.