Investigating the Bonding Performance of Sustainable Steel-GFRP Composite Bars in Reinforced Concrete Structures

Su Zeng^*
*Correspondence: Su Zeng, Department of Civil Engineering, Dongguan University of Technology, Dongguan 523080, China, Email:

Keywords

Sustainable materials • Reinforced concrete • Steel-GFRP

Introduction

The construction industry is undergoing a paradigm shift towards sustainability, driven by concerns over resource depletion and environmental degradation. Concrete, being one of the most widely used construction materials, has come under scrutiny due to its significant carbon footprint and reliance on non-renewable resources such as steel reinforcement. In response, researchers and engineers have been exploring alternative reinforcement materials that offer comparable or superior performance while reducing environmental impact [1]. Among these alternatives, Glass Fiber Reinforced Polymer (GFRP) stands out for its excellent corrosion resistance, high strength-to-weight ratio, and non-conductivity. However, challenges such as lower bond strength with concrete have limited its widespread adoption in structural applications. To address these challenges, hybridization of GFRP with steel has emerged as a promising solution. By combining the advantages of both materials, steel-GFRP composite bars offer enhanced mechanical properties, improved durability, and reduced environmental impact. Despite its potential, the bonding performance between steel and GFRP remains a critical aspect that requires thorough investigation. This study aims to fill this gap by comprehensively evaluating the bonding behavior of sustainable steel-GFRP composite bars in reinforced concrete structures [2].

Literature Review

The literature on composite materials in structural engineering has witnessed a growing interest in recent years, reflecting the industry's shift towards sustainability. Various studies have investigated the mechanical properties, durability, and structural behavior of composite materials, including steel-GFRP composites. Research by demonstrated that hybridizing steel with GFRP can mitigate corrosion-related issues, prolonging the service life of reinforced concrete structures in aggressive environments. Moreover reported that composite bars exhibit superior fatigue resistance compared to conventional steel reinforcements, making them suitable for dynamic loading conditions. However, the bonding behavior between steel and GFRP remains a topic of debate and ongoing research [3]. Early studies by suggested that the bond strength between steel and GFRP is lower than that of conventional steel reinforcement, potentially compromising the structural integrity of reinforced concrete elements. Conversely, recent investigations by proposed innovative surface treatments and interface modifications to enhance the bond strength between steel and GFRP, thereby improving the performance of composite bars in concrete structures. Despite these advancements, there is a need for further empirical research to validate the efficacy of steel-GFRP composite bars in practical applications. Moreover, existing literature primarily focuses on individual aspects such as mechanical properties or durability, lacking comprehensive studies that integrate experimental testing with analytical modeling. This study seeks to address these gaps by conducting a thorough investigation into the bonding performance of sustainable steel-GFRP composite bars, encompassing both experimental characterization and numerical analysis [4].

Discussion

The experimental program conducted in this study involved a series of bond tests to assess the interface behavior between steel and GFRP within a concrete matrix. Specimens were prepared according to ASTM standards and subjected to pull-out tests under varying loading conditions. The results revealed that the bond strength of steel-GFRP composite bars was influenced by factors such as surface preparation, interface roughness, and concrete composition. Surface treatments such as sandblasting and chemical etching were found to improve bond performance by promoting mechanical interlocking and chemical adhesion between steel and GFRP. Furthermore, numerical simulations using Finite Element Analysis (FEA) were employed to complement the experimental findings and provide insights into the underlying mechanisms governing bond behaviour [5]. The FEA models successfully captured the stress distribution along the interface and highlighted the significance of interfacial shear transfer in enhancing bond strength. Sensitivity analyses were conducted to evaluate the effects of material properties, geometric parameters, and loading conditions on the bond performance of composite bars. Overall, the findings suggest that sustainable steel-GFRP composite bars offer promising prospects for use in reinforced concrete structures, provided appropriate surface treatments and design considerations are implemented. By leveraging the inherent advantages of steel and GFRP while addressing their respective limitations, composite reinforcement systems can contribute to sustainable construction practices and mitigate the environmental impact of infrastructure development [6].

Conclusion

In conclusion, this study presents a comprehensive investigation into the bonding performance of sustainable steel-GFRP composite bars in reinforced concrete structures. Through a combination of experimental testing and numerical analysis, key insights were gained into the factors influencing bond strength, durability, and structural behavior of composite bars. The findings underscore the potential of hybrid reinforcement systems to address sustainability challenges in the construction industry while ensuring structural integrity and performance. Moving forward, further research is warranted to explore optimization strategies for composite bar design, including surface treatment techniques, interface modifications, and structural detailing. Additionally, long-term durability studies under real-world environmental conditions are essential to validate the performance and service life of steel-GFRP composite reinforcements. By advancing our understanding of sustainable materials and construction practices, this study contributes to the ongoing efforts towards a more resilient and environmentally conscious built environment.

Acknowledgement

None.

Conflict of Interest

None.

References

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