Theses and Dissertations

Issuing Body

Mississippi State University


Vahedifard, Farshid

Committee Member

Howard, Isaac L.

Committee Member

Ramirez-Avila, John J.

Date of Degree


Original embargo terms


Document Type

Graduate Thesis - Open Access


Civil Engineering

Degree Name

Master of Science


James Worth Bagley College of Engineering


Department of Civil and Environmental Engineering


There is a growing need for employing sustainable soil improvement techniques. Concurrently, soil carbon sequestration methods continue to receive more attention in an attempt to reduce greenhouse gas levels contributing to climate change. Exploring the use of gasifier biochar for soil improvement can possibility address these two needs simultaneously. This study investigates the effect of gasifier biochar amendment on mechanical, chemical and hydraulic properties of a local clay with poor engineering properties. Specifically, strength, swelling, compressibility, collapsibility, permeability, water retention, cation exchange capacity, pH, and microstructural characteristics were determined for the clay amended with 5, 10, and 20% biochar. Two sizes of biochar were used. The results showed that biochar amendment improves the strength, swelling potential, permeability, and water retention properties of the clay. Findings suggest that biochar amendment offers a sustainable solution for improving geotechnical properties of marginal soils while providing an efficient method for biospheric carbon sequestration.