Feasibility of local lime for use in soil stabilization

Abstract

New policies requiring the use of available soils in highway projects have recently been introduced at the New Brunswick Department of Transportation. These policies state that in-situ soils must be incorporated into designs in order to reduce costs. This means that many low strength soils that would normally have been excavated must now be left in place. This has led to a greater emphasis being put on soil stabilization. This study was therefore performed in order to determine if the lime from the Sussex area in New Brunswick is suitable for use in soil stabilization. Soils from the Quisibis River Bridge #1.5 and Southwest Miramichi River Bridge #3 project areas were used in this study. The geotechnical properties of the soils were determined. The soils were then mixed with 3% quicklime content, and were cured for periods of one day, one week, and four weeks. These samples were then tested to determine strength gains, changes in plasticity, and changes in compressibility. The silt from the Quisibis River project site was not significantly improved with the addition of lime. The clay from the Southwest Miramichi project site displayed noticeable improvements in texture, workability, and strength. It also became non-plastic after the quicklime treatment. The change in compressibility of the clay was not as high as some changes reported in the literature, but the clay was still found to be reactive.