Structural Performance of Coir Fiber Crash Barriers: An Engineering Analysis of Safety and Sustainability

Abstract

The coir industry, a traditional sector with deep socio-economic roots in India, is undergoing a critical transformation towards sustainable and value-added applications. As India aims for net-zero carbon emissions by 2050, the transportation sector\'s environmental impact necessitates sustainable infrastructure solutions. This study explores natural coir fiber, a biodegradable byproduct of coconut husks, as an eco-friendly alternative to conventional steel and concrete crash barriers. Focusing on the National Highway Authority of India’s NH66 project, the research evaluates coir’s mechanical properties, including tensile strength and energy absorption, alongside its durability and safety performance through prototype testing and ANSYS crash simulations. Results demonstrate that coir-based barriers offer comparable safety standards to traditional materials while significantly reducing carbon emissions (0.83 kg CO2e/kg versus 1.4–1.85 t CO2/t for steel and 0.93 lb CO2/lb for concrete). Economically, coir barriers are cost-effective at ?410/m compared to ?1586.86–8604.72/m for conventional options, promoting rural livelihoods through coconut industry byproducts. This approach aligns with circular economy principles offering a scalable, low-carbon solution for road safety infrastructure. The findings advocate for further research into coir’s long-term durability and standardized implementation to support sustainable development and climate goals.

Introduction

Climate change and rising emissions from infrastructure—especially in transportation—have driven the need for more sustainable construction practices. In India, transportation contributes nearly 10% of total greenhouse gas (GHG) emissions. Traditional crash barriers, typically made from galvanized steel and concrete, are high in embodied carbon, costly, and environmentally damaging.

To address this, a study explored the feasibility of using natural coir fiber—a biodegradable byproduct from coconut husks—as an alternative material for crash barriers, especially along India’s NH66 highway, where coconut is abundantly grown.

Material and Testing:

• Brown coir fiber (from mature coconuts) was chosen for its superior tensile strength (≈5.9 MPa), density (1200 kg/m³), and energy absorption capabilities.

• Tensile testing on 10–20 mm coir ropes showed breaking loads of 102–214 kgf, indicating sufficient strength for impact absorption.

• Coir’s carbon footprint is low (0.83 kg CO?e/kg), and its processing requires minimal energy and no toxic outputs.

Prototype and Construction:

• A 10-meter prototype barrier was installed on NH66 using:

  • Brown coir ropes,

  • IS 2062 C-section steel posts,

  • Galvanized stay rods.

• The installation was simple, involved manual tools only, and avoided heavy machinery, reducing both cost and emissions.

Simulation and Performance (FEA):

• Using ANSYS 2025 R1, a finite element analysis simulated a 100 km/h vehicle impact.

• Results showed:

  • Max deformation: 0.26314 m

  • Equivalent stress: 24.89 MPa

  • Elastic strain: 1.7311 m/m

• Coir barriers effectively absorbed impact energy and maintained structural integrity, performing comparably to steel systems in redirecting vehicles safely.

Carbon and Cost Analysis:

• Coir barriers reduce emissions by up to 50% and are over 80% cheaper than steel.

• These factors make coir a sustainable and affordable alternative, especially for rural and cost-sensitive regions.

Conclusion

This study establishes natural coir fiber as a viable, sustainable, and economically advantageous alternative to conventional materials for crash barriers in road infrastructure. Experimental evaluations—including tensile testing and computational simulations via ANSYS—demonstrate that coir-based barriers possess the requisite mechanical properties to effectively absorb impact energy, redirect vehicular motion, and maintain safety performance on par with traditional steel and concrete systems. With a measured tensile strength of approximately 5.9 MPa and significant energy absorption capacity, coir ropes exhibit favorable behavior under dynamic loading conditions, while their inherent flexibility mitigates damage to both vehicles and occupants during collisions. From an environmental standpoint, coir\'s low carbon footprint (~0.83 kg CO?e/kg), biodegradability, and minimal processing requirements position it as a critical material in the pursuit of low-impact infrastructure. Its utilization supports circular economy principles by valorizing agricultural waste, thereby diverting biomass from landfills and promoting sustainable waste management practices. The significantly lower unit cost of coir-based barriers (410 INR/m) enhances their feasibility for deployment in both urban and rural settings, making road safety improvements more accessible and equitable across socio-economic strata. The successful prototype deployment along National Highway 66 (NH66) underscores the practical scalability of coir-based barrier systems, especially in regions with abundant coconut cultivation. However, technical challenges remain—particularly regarding moisture resistance, biological degradation, and long-term mechanical stability under varying environmental conditions. Addressing these concerns will require focused research into fiber enhancement techniques, such as bio-based surface treatments, polymer impregnation, or integration into hybrid composite systems. Looking ahead, the standardization and certification of coir-based crash barriers—through regulatory agencies such as the Bureau of Indian Standards (BIS)—will be crucial to ensuring consistent quality, safety, and public trust. Establishing performance benchmarks, conducting field trials across diverse climatic zones, and developing design guidelines tailored to natural fiber systems will further facilitate their adoption in mainstream infrastructure planning. In summary, the integration of coir fiber into road safety infrastructure offers a multifaceted opportunity to align India’s transportation development with its climate mitigation goals. This research provides a robust foundation for policymakers, engineers, and infrastructure stakeholders to pursue a paradigm shift toward environmentally responsible, socially inclusive, and economically viable crash barrier solutions. As India accelerates its transition to a net-zero future, coir-based barriers represent a compelling innovation at the intersection of engineering, sustainability, and rural development.

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Copyright

Copyright © 2025 Dr. Pratheesh G Panicker, Appu John, Finu John, Aban T Rassak, Alu Rose Rajesh, Maimoona A S. 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.