Engineering performance assessment of sustainable coconut coir fiber-reinforced pervious concrete for perforated breakwater design

Source abstract

Background: Coastal erosion has increased the demand for sustainable construction materials capable of reducing wave energy while minimizing environmental impacts. Pervious concrete is considered a promising alternative for perforated breakwaters because of its interconnected pore structure; however, its relatively low mechanical strength remains a major limitation. Aims: This study assesses the engineering performance of coconut coir fiber-reinforced pervious concrete for perforated breakwater applications by evaluating its mechanical and hydraulic properties. Method: An experimental study was conducted using coconut coir fiber contents of 0%, 1%, 3%, 5%, and 7% by weight of coarse aggregate. Concrete specimens (150 × 150 × 150 mm) were cured for 28 days under freshwater and seawater conditions. Compressive strength, porosity, water absorption, and infiltration rate were measured to determine the optimum fiber content. Results: Increasing the fiber content enhanced porosity, water absorption, and infiltration capacity but reduced compressive strength. The 5% fiber mixture exhibited the most balanced performance, with porosity values of 14.84% in freshwater and 15.35% in seawater while maintaining acceptable mechanical properties for porous concrete. Conclusion: Coconut coir fiber can improve the hydraulic performance of pervious concrete and represents a sustainable alternative for perforated breakwater design. However, further optimization is required to achieve the compressive strength required for primary coastal protection structures.