Performance Evaluation of Eco friendly M30 Concrete with Recycled Steel Fiber

Abstract

This study examines the performance of sustainable M30 concrete reinforced with Recycled Steel Fibers (RSF) obtained from waste steel scrap. RSF was added at 1%, 1.5%, 2%, 3%, and 4% by weight of cement, and the concrete was tested for compressive, split tensile, and flexural strength. Results showed that RSF improved tensile strength, flexural strength, ductility, and crack resistance through effective crack bridging and energy absorption. Optimal performance was achieved at 2–3% fiber content, balancing strength enhancement and workability, while higher fiber content reduced workability despite increased toughness. The study concludes that recycled steel fibers can effectively enhance concrete performance while promoting sustainable and resource-efficient construction practices.

Introduction

This study investigates the use of recycled steel fibers in M30 grade concrete as a sustainable alternative to conventional concrete. Cement production contributes significantly to carbon emissions and resource depletion, creating a need for eco-friendly construction materials. Recycled steel fibers obtained from waste steel scrap, discarded tires, and industrial waste are incorporated into concrete to improve performance while promoting waste utilization and environmental sustainability.

The primary objectives of the study were to develop an eco-friendly concrete mix, evaluate improvements in compressive and flexural strength, determine the optimum fiber dosage, validate recycled steel fibers as a sustainable reinforcement material, and assess their cost-effectiveness compared to conventional reinforcement.

The materials used included cement, fine aggregate, coarse aggregate, potable water, and hooked-end steel fibers. The concrete mix maintained a water-cement ratio of 0.43 to achieve the target strength of M30 concrete. The steel fibers possessed high tensile strength (800–1200 MPa), excellent elasticity, and strong crack-bridging capabilities.

Experimental tests were conducted to evaluate workability (slump test), compressive strength, and flexural strength for different fiber contents.

Key findings include:

• Workability: Slump values decreased as fiber content increased, indicating reduced workability due to higher stiffness and internal friction caused by the fibers.
• Compressive Strength: Strength improved as fiber content increased up to about 2%, where optimum performance was achieved. The fibers enhanced crack control and matrix bonding. Beyond 2–2.5%, workability and compaction difficulties led to void formation and a decline in compressive strength.
• Flexural Strength: Flexural performance increased significantly with fiber addition, reaching maximum values at approximately 2% fiber content. Although strength gradually decreased at higher fiber percentages, fiber-reinforced concrete continued to outperform conventional concrete.

The study concludes that recycled steel fiber reinforced concrete (RSFRC) significantly improves strength, toughness, crack resistance, ductility, and durability while reducing environmental impact through waste recycling. An optimum fiber content of around 2% provides the best balance between mechanical performance and workability. The material is suitable for applications such as industrial floors, pavements, bridge decks, and other structures requiring enhanced durability and toughness, making it a promising solution for sustainable and green construction practices.

Conclusion

1) Eco-friendly M30 concrete was successfully developed using recycled steel fibers (RSF) obtained from waste steel materials. 2) The inclusion of RSF improved the compressive, tensile, and flexural strength of concrete compared to conventional concrete. 3) Recycled steel fibers enhanced crack resistance, toughness, and energy absorption capacity by controlling crack propagation. 4) Optimum performance was observed at 2–3% fiber content, which provided a good balance between strength and workability. 5) Higher percentages of RSF increased toughness and ductility, although workability of concrete was reduced. 6) The study proved that recycled steel fibers can be effectively used as a sustainable and economical reinforcement material in concrete.

References

[1] A. Naaman, High Performance Fiber Reinforced Cement Composites, CRC Press, 2021. [2] R. Buswell et al., “3D printing using concrete extrusion: A roadmap for research,” Cem. Concr. Res., vol. 112, pp. 37–49, 2018. [3] F. Dilsiz, “Historical evolution of fiber addition in construction,” J. Build. Mater., vol. 15, no. 4, pp. 255–268, 2019. [4] J. Romualdi and G. Batson, “Mechanics of crack arrest in fiber reinforced concrete,” J. Am. Concr. Inst., vol. 60, pp. 37–58, 1963. [5] P. Rossi, “Steel fiber reinforced concrete behavior,” Mater. Struct., vol. 19, pp. 47–56, 1986. [6] H. Yaz?c? et al., “Hybrid FRC with improved flexural response,” Constr. Build. Mater., vol. 262, pp. 120–135, 2021. [7] F. Altun, “Effects of steel fiber addition on mechanical properties,” Mater. J., vol. 110, no. 3, pp. 327–336, 2013. [8] J. Mindess et al., Concrete, 3rd ed., Pearson, 2020. [9] K. Holschemacher, T. Klug, and A. Mueller, “Behavior of FRC slabs under flexural loading,” Mater. Struct., vol. 55, pp. 75–86, 2022.

Copyright

Copyright © 2026 Kruthika V R, Mandhara M B , Muhammed Aasif T, Pavan Naik, Suraj M Shet, Swapna S A. 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.