Shrinkage Characteristics of Expansive Soil Treated with Coir Waste

Coir waste is an environmental friendly waste accumulating drastically in coir manufacturing countries all over the world. Coir waste composes of two components, coir pith and short coir fibres. This paper presents studies on the shrinkage characteristics of coir waste mixed expansive soil by varying coir pith from 0 to 3 % and short coir fibre from 0 to 1 % by dry weight of soil. The results showed that the addition of coir pith and short coir fibre effectively controls the shrinkage characteristics of expansive soil. The shrinkage indices were computed by equations given in IS 2720 (Part 6), BS 1377:1990, ASTM D 653-03 as well as from Ranganatham and Satyanarayana (1965). Shrinkage indices by BS and Ranganatham and Satyanarayana are found to be more realistic than that obtained by the other methods. The volumetric shrinkage was obtained from shrinkage limit test and three dimensional shrinkage strain test. It was found that three dimensional shrinkage strain test is more reliable for computing the volumetric shrinkage than shrinkage limit test. © 2015, Indian Geotechnical Society.