Experimental Study on the Behavior of Reinforced Concrete Beams Reinforced with BFRP Bars

Abstract

This research investigates the structural performance of reinforced concrete (RC) beams reinforced with Basalt Fiber Reinforced Polymer (BFRP) bars. The study aims to determine the tensile, flexural, and torsional performance of BFRP-reinforced beams as an alternative to traditional steel reinforcement. Experimental tests including tensile strength tests, flexural strength tests, and torsional strength tests were conducted on both BFRP and steel reinforced beams. Results demonstrate that while BFRP bars provide corrosion resistance and lower density, they exhibit lower stiffness and a linear elastic behavior until failure. The findings support the viability of BFRP bars in non-prestressed structural applications, particularly in corrosive environments.

Introduction

FRP bars, especially BFRP and GFRP, are emerging as alternatives to traditional steel reinforcement in concrete structures, particularly in corrosive environments. These materials offer benefits such as:

• High tensile strength

• Corrosion resistance

• Low weight

However, they come with challenges:

• Low ductility

• Lower modulus of elasticity

• Brittle failure modes

II. Key Literature Insights

1. Alsayed et al. (2000):
   Modified ACI models effectively predict flexural behavior of GFRP-reinforced beams; improved deflection estimates at service loads.

2. Wu et al.:
   Reviewed BFRP’s strengths and its integration with hybrid systems (e.g., Carbon FRP and steel). Long-term performance still requires more research.

3. Urbanski et al.:
   Experimental study of BFRP-reinforced beams highlighted strength but noted concerns over brittle failure and bond-slip behavior.

4. Inman et al. (2016):
   Compared BFRP and steel in terms of performance and sustainability. BFRP showed lower stiffness but better environmental impact.

5. Hadi and Yuan (2017):
   Found that combining steel with GFRP increased ductility. GFRP alone led to brittle, low-stiffness behavior.

6. Hollaway and Teng (2008):
   Emphasized FRP advantages (lightweight, corrosion resistance), but also limitations (bond behavior, fire resistance, durability).

7. Bank (2006):
   Discussed FRP mechanical properties and benefits (non-corrosive, strong), but noted issues with cost, brittleness, and code standardization.

8. Nanni and Dolan (1993):
   Early study showing FRP bars had good bond and strength, urging for formal design guidelines and more field validation.

III. Objectives of the Study

1. Evaluate flexural performance of RC beams reinforced with BFRP.

2. Compare tensile performance of BFRP vs. steel rebars.

3. Assess BFRP’s viability as a steel replacement in RC structures.

IV. Methodology

• Concrete: M30 mix, designed per IS 10262.

• Materials tested: Cement, aggregates, BFRP, steel rebars.

• Specimens: RC beams cast with both BFRP and steel reinforcement.

• Tests: Tensile, flexural, and torsional tests conducted after 7 and 28 days of curing.

V. Results and Discussion

A. Tensile Test Results

• BFRP bars are significantly stronger in tension but fail brittly.

• Steel bars exhibit yielding and necking, indicating higher ductility.

B. Flexural Test

• BFRP-reinforced beams showed lower deflection but also lower ductility compared to steel.

• Behavior remained linear elastic up to failure.

C. Torsional Test

• Steel-reinforced beams absorbed more energy under torsion, showing better toughness.

Conclusion

BFRP bars offer a corrosion-resistant alternative for reinforcing RC beams in aggressive environments. Despite their limitations in ductility and modulus of elasticity, they are suitable for structures requiring high durability and low maintenance. Further studies are suggested for long-term performance evaluation and hybrid reinforcement strategies.

References

[1] Alsayed, S.H., et al. (ACI Model Modifications for GFRP Reinforcement) [2] Wu, Z., et al. (BFRP in Infrastructure Applications) [3] Urbanski, M., et al. (Comparative Study on BFRP and Steel Reinforced Concrete) [4] Inman, M., et al. (Environmental and Mechanical Performance of BFRP) [5] Hadi, M.N.S., et al. (Flexural Behavior of Composite Beams with GFRP)

Copyright

Copyright © 2025 Shaik Nawaz Shareef Ramzane. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.