Experimental Study on Improvement of Local Subgrade Soil for Road Construction by Coir Fibre, Sisal Fiber and Basalt Fiber

Now a days in infrastructure developments many waste materials are generated. Waste materials like coir fiber, sisal fiber, basalt fiber, fly ash, plastic waste, marble chips etc. are used in highway construction. Coir fiber, extracted from the husk of coconuts, is one of the toughest natural fibers available. Its exceptional durability and eco-friendliness make it highly advantageous for various applications, including soil erosion control, soil reinforcement, and stabilization. Compared to other natural fibers, coir stands out due to its strength and sustainability, making it a preferred choice in many industries. Since coir is an environmentally friendly material, its use does not cause harm to nature, ensuring sustainable utilization without negative environmental impacts. Although often considered a by-product of the coconut industry, coir is actually a recycled waste material harnessed for its beneficial properties. India, known for its extensive use of coconut palms, has long recognized the value of coir in producing fiber-based and woven products. The preference for coir composites is driven by key factors such as mechanical reliability, durability, recyclability, cost-effectiveness, and ease of disposal at the end of their lifecycle. These attributes make coir a practical and sustainable alternative for various industrial and environmental applications. Sisal fiber is derived from leaves of plant. It is usually obtained by machine decortications. The strands of coir fiber are typically creamy white, measuring between 80–120 cm in length and 0.2–0.4 mm in diameter. They have a lustrous appearance, adding to their visual appeal. In comparison, sisal fibers are smooth, straight, and yellow in color. Sisal is relatively coarse and inflexible, and its fibers can vary in length, ranging from short to long strands. Sisal is highly valued for cordage applications due to its strength, durability, stretchability, and affinity for certain dyes. Additionally, it exhibits excellent resistance to deterioration in saltwater, making it a preferred material for marine ropes, mats, and other industrial uses.