Experimental study on strength properties of problematic soils with RBI – 81 stabiliser

Rapid industrialization demands for developing engineering facilities even in difficult soils like soft clays and loose silts. Expansive soils which are generally termed as problematic soils cause swelling and shrinkage resulting in significant damage to the structures constructed on them. In this study an attempt is made to improve the strength and to stabilize the problematic soil by the use of chemical additive, RBI grade 81. Detailed experimental investigation including unconfined compression tests, SEM and EDAX analysis were carried out to know the effectiveness of addition of RBI grade 81 to improve the engineering properties, chemical composition and mineralogical properties of two soil samples (A1 and A2). Treated soil specimens at various stabilizer dosages (2, 4 and 6%) were tested for UCS after curing periods of 3 days and 7 days. It was observed that the unconfined compressive strength of the soil sample A1 and A2 increased by 475% and 430% with addition of 6% stabilizer after 7 days curing. The increase in strength can be due to the formation of new cementitious compounds which is evident in the micrographs from SEM and EDAX analysis.