Strength Property of Expansive Soils Treated with Bagasse Ash and Lime

Abstract

Minimising the cost of stabilisation and improving the load bearing capacity of expansive soils are major concerns to geotechnical engineers dealing with road construction over problematic subgrades. Bagasse ash, an agricultural waste by-product, may be used to improve the bearing capacity of expansive soil, treated with lime as well as to solve the disposal problem caused by bagasse ash which is an environmental challenge. The primary goal of this experimental research is to examine the feasibility of using bagasse ash with lime as a soil stabilisation technique. Various contents of hydrated lime, i.e. 2.5%, 4.5%, and 6.25% with different percentages of bagasse ash depending on the combination ratio of lime to bagasse ash, were used in this study. The mixing ratio between lime (L) and bagasse ash (BA) was sandwiched between 1:1 and 1:5 to obtain the optimum mix for stabilising expansive soil. The effects of stabilisers were evaluated through an array of experimental tests including unconfined compressive strength (UCS) tests at different curing times (3, 7, 28, and 90 days). The durability properties were also investigated through studying the influence of water immersion (7 days) on UCS and wetting-drying cycles on UCS after the samples were cured for 28 days. The experimental results showed that the UCS of samples with the mixing ratio of 1:3 when the lime content was 6.25% resulted in a better improvement than 6.25% lime-soil without adding bagasse ash. The findings of this study revealed that bagasse ash in combination with hydrated lime could be used as a pozzolanic material in soil stabilisation to reach the target strength.