Glass fibre reinforced polymer panels for sustainable retaining wall systems

Reinforced cement concrete (RCC) panels are widely used in reinforced earth retaining structures for transportation infrastructure. However, the high embodied carbon and greenhouse gas emissions associated with cement-based materials necessitate the development of sustainable alternatives aligned with the goals of United Nations Sustainable Development Goal 11. Glass fibre-reinforced polymer (GFRP) composites offer advantages such as high strength-to-weight ratio, corrosion resistance and durability, making them promising materials for sustainable geotechnical infrastructure. This study evaluates the feasibility of corrugated GFRP sandwich panels as an alternative to RCC panels in reinforced earth retaining systems. Panels were fabricated using glass fibre and epoxy resin through a hand lay-up technique. Tensile, lap-shear and flexural strengths were determined in accordance with relevant codal provisions. A panel measuring 0.52 m × 0.60 m × 25 mm was tested under reinforced backfill with relative densities of 35%, 55% and 75%, and surcharge loads up to 20 kPa. The GFRP specimens exhibited linear elastic behaviour up to brittle failure, with an average tensile strength of 161.3 MPa and Young’s modulus of 8.80–11.37 GPa. Reinforced earth wall tests showed pressure responses consistent with theoretical predictions and negligible deformation, demonstrating that GFRP panels can serve as a sustainable alternative to RCC panels.