Stabilizing Using Cement and Lime for Sub Grade Improvement: A Case Study Fiche Town.

Abstract

Expansive soils are known for their volume changes with seasonal moisture fluctuations. It swells when it gets wet and shrinks during the dry season. Seasonal changes in the volume of expansive soil cause significant damage to infrastructure. Due to this complex behavior, expansive soil should be treated properly or avoided when used as foundation soil and in subgrade road construction. This study is aimed at improving the bearing capacity of the expansive soils in Fiche town by stabilizing them with cement and lime. Two representative samples were collected from selected sites in Fiche town using purposive sampling. Various geotechnical tests were carried out to characterize the expansive soil. The test results show that both soils were found to be highly plastic clay soils (CH or A-7-5). After the soil was checked to be expansive soil, different percentages of cement and lime were added to treat the natural soil. The improvement was evaluated by adding 3%, 5%, 7%, and 9% of hydrated lime and 3%, 5%, 7%, 9%, 11%, 13%, and 15% of cement by weight. The findings of the laboratory tests indicate that the plastic index of the naturally expansive soils decreased with the addition of cement and lime, on average, from 49.1% to 13.2% for cement and from 49.1% to 10.9% for lime stabilizers. The value of CBR increased from 1.48% to 16.5% and from 1.48% to 9.8% when stabilized with cement and lime, respectively. Generally, the addition of cement and lime resulted in significant improvements in CBR, free swell, CBR swell, plastic index, and compaction characteristics. In this study, the minimum requirement requested by the ERA standard was achieved with 7% of cement and lime addition. Hence, from the above-mentioned results, it was concluded that the use of cement and lime improves the engineering properties of expansive soil. Additionally, the researcher would recommend that further research should concentrate on the impact of cement and lime as stabilizers on consolidation properties