EGG SHELL ASH AS AUXILIARY ADDENDUM TO LIME STABILIZATION OF AN EXPANSIVE SOIL.

James, Jijo; Pandian, P. Kasinatha; Switzer, A. Snowline

The study involved the utilization of egg shell ash (ESA) as an auxiliary addendum to lime in stabilization of an expansive soil with the objective of evaluating its potential in augmenting the performance of lime. Locally available soil was excavated and transported to the lab where it was characterized and found to be high plastic clay of expansive nature. The minimum lime required for modification of this soil was determined using the Eades and Grim pH test and was found to be 4%. ESA was obtained by controlled combustion of egg shell powder in a muffle furnace at a temperature of 500°C for three hours. This ash was used as additive to 4% lime in three doses of 0.5%, 1% and 2%. The soil to be stabilized was mixed with 4% lime which formed the control specimen along with other combinations of lime and ESA and were moulded into cylindrical samples for determination of their uniaxial compressive strength. The samples were cured for periods of 7 and 28 days, followed by strength, plasticity and mineralogy tests. The results of the tests indicated that the addition of ESA to lime stabilization resulted in enhanced early as well as delayed strength and reduced plasticity. The strength of the lime stabilized soil increased from 171.87 kPa to 213.86 kPa for 2% addition of ESA at 28 days of curing. This translated to a strength gain of 24.43%. The plasticity of the lime stabilized soil reduced from 21.46% to 13.93% for 2% ESA amendment. Mineralogical analysis revealed the formation of calcium silicate and calcium aluminate hydrate minerals.

SWELLING soils; LIME (Minerals); CLAY; COMBUSTION; COMPRESSIVE strength

Journal of Solid Waste Technology & Management, 2017, Vol 43, Issue 1, p15

1088-1697

Academic Journal

10.5276/JSWTM.2017.15