Strength Characterization of Expansive Soil Treated with Phosphogypsum and Crumb Waste Rubber

摘要

Expansive soils often exhibit volumetric changes with variations in the seasonal moisture. Pavements constructed on expansive soil subgrades may subject to cracking, waviness, and distress. This paper reports the laboratory CBR and UCS test results conducted on expansive soils treated with phosphogypsum (PG) and crumb waste rubber (CRW). The influence of several mix proportions of PG-CRW on the strength properties of expansive soil was studied through experimentation. A significant improvement was observed in the CBR and UCS values, at optimum percentages of 6% and 2% respectively for PG and CRW. Further, the durability of the proposed mix proportions was interpreted from the soil samples subjected to curing for 28 days. An attempt was made to correlate the CBR and UCS values of the treated soil matrix through linear regression analysis. The results of the study can be gainfully utilized in the design pavement subgrades on soft soils.