Performance evaluation of natural fiber reinforced Laterite soil for road pavement construction

The growing urbanization needs a good road network. A durable subgrade always supports a road for a longer period to perform better. The serviceability of roads largely depends on the flexibility of the highways to withstand heavy cyclic loads appearing in a repeated manner. The prolonged application of such important roads was improved using chemical and industrial wastes, by-products, and costly geosynthetic fibers in various proportions varying from site to site requirement. Laboratory condition fits the chemical and synthetic additives to enhance the strength of soil in controlled temperature and humidity used in the subgrade. A problem arises in rapid and low-budget road construction in an open exposure field condition which includes abrasiveness, temperature fluctuations, lubrication due to water, erosion, chemical and biological degradation, etc. Due to high cost and high-quality control requirements in the field, Geosynthetics are not always the first choice for road engineers. As alternative natural fibers are getting popularity for increasing the tensile load carrying capacity of subgrade soil and to reducing the application of industrial by-products which causes green house gas emission during production and also synthetic fibers. The cellulose of natural fibers mainly provided the rupture strength which enhances by removing lignin and pectin from fibers using lime (NaOH) treatment soaked for 4 days. The surfaces of the fibers (Cocnut + Areca) are coated with low viscous bituminous emulsion tar to increase the durability of the fiber-reinforced soil matrix. After pre-treatment, natural fibers are thoroughly mixed with soil in two separate ratios of 0.3% and 0.6% having two different lengths of 30 mm and 60 mm were taken to observe the modifications in the physical and mechanical properties of fiber-reinforced soil matrix using the same curing time. The compaction properties, workability, strength, and permeability properties were taken into consideration. Among four different combinations, 0.3%-0.6% dosage having the equal contribution of 30 mm coconut fiber and 30 mm areca tree fiber was found to be an optimum choice in sub-grade construction. Copyright (c) 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Second International Conference on Engineering Materials, Metallurgy and Manufacturing.