Use of Coir Fibers for Improving the Engineering Properties of Expansive Soils

ABSTRACT

A large part of Central India and a portion of South India are covered with black cotton soils. These soils have high swelling and shrinkage characteristics and shear strength is extremely low; hence, there is need for improvement of these properties. Coir is a natural biodegradable material abundantly available in some parts of South and coastal regions of India. The paper reports the results of comprehensive experimental investigations using tri-axial shear tests, swelling, and consolidation tests to quantify the improvement of strength, swelling and compressibility characteristics of black cotton soil reinforced with coir fibers in a random manner. This paper discusses the mechanisms of improvement in strength, shrinkage, swelling and compressibility behavior of black cotton soils due to the inclusion of coir fibers. This facilitates the use of combination of black cotton soil and coir fibers for sustainable development purposes.

KEYWORDS:

• Coir fibers
• expansive soils
• improvement
• properties
• strength
• compressibility swelling

The authors thank the reviewers for a critical review and constructive criticism which have been useful in revising the draft and in bringing it to the present form. The work presented in this paper is a part of the research project on the use of coir as drainage medium for soft ground improvement and as random reinforcing material supported by Coir Board, Ministry of Agro and Rural Industries, Government of India. The authors thank the Board for the financial support.

Notes

ASTM Standards. 2004. Standard Test Methods for One-Dimensional Consolidation Properties of Soils Using Incremental Loading. ASTM D 2435–04.

ASTM Standards. 2003. Standard Test Method for Unconsolidated Undrained Triaxial Compression Test for Cohesive Soils. ASTM D 2850–03a.