Long-term Performance Studies on Strength Characteristics of Black Cotton Soil Reinforced with Untreated and Treated Coir Fibre

Abstract

Strength retention on the long run can be improved by making coir fibres less water absorbent. In the present study, coir fibres have been alkali treated and admixed in black cotton soil. Use of untreated and treated coir fibres (UCF and TCF) to black cotton soil is comparatively investigated in terms of UCS using remoulded specimens compacted with wide range of dry densities and water contents on the basis of compaction test. Long-term performance is evaluated by curing the remoulded specimens for periods ranging from 0 to 360 days. The test results indicated that the strength of black cotton soil reinforced with UCF and TCF is significantly affected by fibre content, dry density and water content and changes the failure behaviour from brittle to ductile. Long-term performance can be significantly improved by using treated coir fibres, in which the reduction in strength of black cotton soil admixed with treated coir fibres indicated marginal loss of strength, at around 21.16%.