Performance Evaluation of Palm Oil Fuel Ash for Residual Soil Stabilization

This paper provides a detailed investigation into the possible application of palm oil fuel ash (POFA) as a soil stabilizer for kaolinite-rich laterite soil. Extensive research has been conducted on POFA, a by-product of palm oil processing, owing to its potential engineering properties. When used as an additive to soil, POFA has shown promising results in terms of improved shear strength and durability. The study is specifically focused on analyzing the impact of POFA on kaolinite-rich laterite soil, which is commonly used in construction in southern Kerala. The pozzolanic properties of POFA are attributed to its effectiveness in stabilizing the soil. Standard proctor tests, unconfined compressive strength (UCS) tests, CBR tests, and wetting–drying tests were conducted on both untreated and the Soil-POFA-treated mixes. The POFA dosage was varied from 0 to 60% by weight of the soil to determine the ideal dosage for soil stabilization. Additionally, to assess the pozzolanic effect of POFA, we analyzed the microstructure of the unstabilized and stabilized soil mixes using SEM analysis. The specimens were cured for 1 and 7 days. According to the findings, the incorporation of POFA into the kaolinite-rich laterite soil led to a notable improvement in its strength and durability, indicating that it is a feasible choice for construction applications. SEM images provided additional evidence supporting the formation of cementitious gels and alterations in soil porosity resulting from the inclusion of POFA.