FLY ASH STABILIZED LATERITIC SOIL AS SUBBASE MATERIAL: A REVIEW

The aim of this review is to gain insights of the geotechnical properties of lateritic soil that make it suitable to be used as a subbase material, and discuss the improvements done on the properties to further strengthen them. Several additives are reviewed for the lateritic soil stabilization, and fly ash is chosen to be the material of interest. This is so to answer the problem statement of would fly ash be a potential material for soil stabilization. Based on this review, it is understood that lateritic soil is commonly found in tropical and subtropical regions and is classified as sandy clay or silty clay. Studies also have shown that fly ash is potential to be used as a stabilizer in soil improvements. The presence of free lime may react with the silicates and aluminates, resulting to a long-term strength gain in soil. Class C fly ash contains more free lime that would lead to better strength gain in the earlier stage as compared to Class F fly ash. In addition to that, the particle size of the fly ash would also affect the improvement results, as smaller particle size allows more effective surface for the pozzolanic reaction to occur. The significance of this review is to show the potential of fly ash in improving lateritic soil, other than providing more evidence to encourage the incorporation of industrial waste in soil stabilization.