Recycled Jute Fiber Utilization for Soil Strengthening and Pavement Design Improvement

Recycled Jute Fiber Utilization for Soil Strengthening and Pavement Design Improvement

The purpose of the study is to establish recycled jute fibers as a natural soil reinforcement agent, resulting in additional benefits in terms of the economy of an infrastructure project like pavement construction. First, sand is mixed with fibers extracted from used gunny bags. Subsequently, a series of tests, including the compaction test, the California Bearing Ratio (CBR) test, the Unconfined Compressive Strength (UCS) test, and Direct Shear Test (DST), are conducted to evaluate the strength of the subgrade soil. Fibers of lengths 0.5ʺ, 1.0ʺ, 1.5ʺ, and 2.0ʺare mixed in proportions of 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, and 4.0% in the soil. A typical pavement section is designed in IITPAVE software for both subgrades, i.e. normal and fiber mixed. The design is done for the traffic loading of 30 MSA (Million Standard Axles), 50 MSA, and 100 MSA. A subsequent cost analysis highlights the reduction in thickness and, thereby, the reduction in project cost for the different cases.
The study found that the densest packing and highest shear strength are obtained with 0.5ʺfibers mixed in 0.5-1%. The CBR values increase till 1.5% fiber content for each fiber length studied, with a maximum obtained for 2ʺ. Additionally, the study concludes that adding 1.5% of 2 fiber to the pavement subgrade reduces the total pavement thickness. Specifically, crust thickness decreases from 610 mm to 540 mm for 30 MSA traffic, 670 mm to 590 mm for 50 MSA traffic, and 790 mm to 710 mm for 100 MSA traffic. The cost of construction can be reduced by 27.64% for 30 MSA traffic, 25.96% for 50 MSA traffic, and 41.75% for 100 MSA traffic.