Experimental Studies on Influence of Alccofine and Calcium Chloride on Geotechnical Properties of Expansive Soil

Abstract

Expansive soil deposits occur in the arid and semi-arid regions in the world. They cover a major portion on the geographical area in the world and about one-fifth the area of India (approximately 300,000 km2); such soils are popularly perceived as black cotton soils and found extensively in Andhra Pradesh, Gujarat, Karnataka, Madhya Pradesh, Maharashtra and Tamil Nadu. The present study is to elucidate and efficacy of materials as an additive in improving the engineering characteristics of expansive soils. An experimental programme has evaluated the effects of alccofine-1203(3%, 6% and 9%) and Cacl2 (0.25%, 0.5%, and 1.0%) contents on the FSI, swelling potential, swell pressure, plasticity, compaction, strength, hydraulic conductivity, SEM, XRD, cation exchange capacity (CEC), characteristics of expansive soil. Both admixtures were added independently and blended to the expansive soil. Mixing of both admixtures into expansive soil results shown that plasticity index, hydraulic conductivity, swelling properties of blends decreased and dry unit weight and unconfined compressive strength is increased in combination of soil + 6% of alccofine-1203 + 1% Cacl2, but further more addition of alccofine-1203 and Cacl2 leads to decrease in the unconfined compressive strength. It was found that the optimum quantity of material for favourable combination of soil + 6% of alccofine-1203 + 1% Cacl2 was taken for further study in view of its economy due to lower Cacl2 content.