Valorisation of egg shell ash as a potential replacement for lime in stabilization of expansive soils

Abstract

The investigation focussed on the possibility of replacing lime in soil stabilization using Egg Shell Ash (ESA), a waste derived from poultry industry. An expansive soil was characterized for its properties in the lab. The minimum lime content required for modification of soil properties was determined from the Eades and Grim pH test. This lime content came out to be 3%. The lime content was replaced using ESA in the proportions of 33%, 50%, 67% and 100%. Unconfined compression test specimens of dimension 38 mm x 76 mm were cast for different combinations and were cured for periods of 3, 7 and 28 days. Samples were also subjected to 1, 3 and 5 cycles of wetting and drying to understand its durability. After the designated curing periods and cycles of wetting and drying, they were strained axially till failure. Atterberg limits tests were done to determine the plasticity of the stabilized soil. The strength results indicated that ESA cannot be used under normal conditions as a replacement for lime, however, ESA replacement resulted in good durability of the specimens under conditions of wetting and drying. It was concluded that ESA replacement of lime can be adopted in conditions of wetting and drying.

Durability performance of a lime stabilized expansive soil with egg shell ash as a subsidiary admixture

“…On the whole, when the ESA/lime ratio is lower than 0.5, the strength values are higher. This is somewhat in agreement with the conclusion given by James et al [12], who recommended adopting ESA/lime ratios of less than one. Another important point to be noted is that in the work done by James et al [12], ESA was used as a replacement for lime, as a result of which the minimum quantity of lime required for stabilization was not maintained.…”

“…Very few researchers have addressed this in their investigations, especially since the combination of lime and eggshell ash is virtually absent in literature. Two earlier studies done by James et al in the year 2017 [4] and 2020 [12] were considered for comparison due to their similarities with the present study viz. use of combinations of lime and ESA in stabilization of a highly plastic soil.…”

“…Figure 3 shows a comparison between the present study and earlier studies involving ESA. In order to bring in the effect of both the stabilizers into the comparison, the composition of the stabilizers has been reduced to an ESA/Lime ratio as done in some earlier investigations [12], [25], [26]. Most of the work with egg shell waste predominantly deals with egg shell powder.…”

“…They found that ESA could replace up to 30% of cement without much loss in the strength of the block. James et al [12], in a later investigation, attempted to study the potential of ESA as a potential replacement for lime in the stabilization of lime under conditions of wetting and drying (WD). They found that increasing ESA in the mix resulted in more durability of the stabilized soil.…”

Potential of Portland pozzolana cement in the stabilization of an expansive soil subjected to alternate cycles of wetting and drying

“…This was followed by 24 hours in open air at room temperature which constituted one cycle of drying. Similar procedure has already been reported in literature [20], [21]. The samples were subjected to 1, 2 and 3 cycles of wetting and drying.…”