Effect of utilization of silica fume in the strength and swell characteristics of expansive soil

• Main Authors: Janani, V., Debnath, Manas, Ravichandran, P. T.
• Format: Conference Proceeding
• Language: English
• Subjects: Bearing strength; California bearing ratio; Compressive strength; Curing; Dosage; Dry density; Expansive soils; Lime soil stabilization; Moisture content; Penetration tests; Pozzolans; Silica fume; Soil compaction; Soil compression tests; Soil improvement; Soil lime; Soil moisture; Soil properties; Soil stabilization; Soil strength; Soil swelling; Soil testing; Waste materials
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0236330

The soil beneath the foundation is the most important part of a construction, in case the soil being expansive and problematic, due to which it has low bearing strength then it has to be studied properly and enhanced for a safe and better construction. Soil stabilization is one of the most important methods that are used to enhance soil properties. Traditional methods include Lime stabilization, Bitumen stabilization etc. but improvement of soil can also be done at a low cost by using waste materials. For this study, Silica Fume as a waste material has been used at different percentages (2.5%, 5%, 7.5%,10% and 12.5%) as replacement by dry weight of the soil for varying curing periods (3, 7, 14, 28,) days. Laboratory experiments performed are Standard Proctor Compaction, Unconfined Compressive Strength, California Bearing Ratio and Free Swell Test to know the compaction, strength and swell properties of the virgin as well as treated soil and figure out the optimum dosage of replacement of the additive to improve on these properties of the soil. The test results indicated that Optimum Moisture Content increased by about 11.11% at 20% dosage and the Maximum Dry Density decreased by 7.9%. In the case of Unconfined Compressive Strength for 10% dosage the Silica Fume showed an increase in strength of about 348% for 14 days curing. Similarly,the California Bearing Ratio test showed highest strength increase for 10% replacement with respect to virgin soil. The replacement of Silica Fume in certain percentages showed a higher increase in strength from which 10% showed the highest results which can be regarded as the optimum percentage. The Silica Fume is a type of by-product of the metal silicon as a waste material which can be used as a binding material in stabilizing problematic clay as it is a very reactive pozzolanic material which can lead to a reduced cost enhancement other than consideration of conventional methods.