Early Strength of an Expansive Soil Stabilized Using a Blend of Hydrated Lime, Unrefined Brown Sugar and Ground Gallnut Dust Under Varying Curing Conditions

The present investigation attempts to use a traditional blend of unrefined brown sugar (UBS) and ground gallnut dust (GGD) with lime in augmenting the strength of a virgin soil of swelling nature. A swelling soil from Thaiyur area in Chengalpattu district was collected and characterized in the laboratory. The least lime dose needed to alter the characteristics of the soil known as the lime modification optimum (LMO) was determined as 5% using the Eades-Grim pH test as per ASTM code D6276. For evaluating the unconfined compression strength (UCS), cylindrical soil samples of size 3.8 cm × 7.6 cm were formed to evaluate the strength of all blends. All test specimens were kept aside for curing for a duration of three days to evaluate the strength. Soil cylinders were moulded to a target density and water content identified from mini compaction test. The ideal ratio of lime, UBS and GGD came out to be 5:1:1. The specimens stabilized with ideal dosage were exposed to air curing, moisture curing and thermal curing for a period of three days. The ideal blend was also subjected to 0, 1 and 2 cycles of wetting–drying (WD) to get a preliminary indication of its durability. The outcome of the work indicated that temperature curing was the most conducive for the progress of initial strength of the combination. WD results in loss of strength in the first cycle. However, the loss of strength in the second cycle was similar to first cycle. The study concluded that the usage of this traditional blend has potential in treatment of swelling soils, but more detailed investigations as to the role of the individual components need to be probed further.