Application of lime-rice husk ash mixture (LRHA) for the stabilization of fine-grained soil: a state-of-the-art review

The rapid growth of population and urbanization has created an immense demand for infrastructural development, urging researchers to seek solutions for utilizing problematic lands in construction projects. Traditional soil stabilizers like lime and cement raise environmental concerns due to significant greenhouse gas emissions during their production. RHA (rice husk ash) is an agricultural by-product that is generally dumped as waste material. However, many studies have established RHA as an excellent silica source and explored its potential as a soil stabilizer. The incorporation of RHA along with lime or cement can reduce the amount of these conventional stabilizers required for the treatment of soil. This scientific review paper offers a comprehensive overview of previous studies by various researchers, highlighting the use of LRHA (lime-RHA mixture) in the modification of fine-grained soil, its effectiveness in enhancing soil performance, and its potential for sustainable infrastructure development. LRHA treatment reduces the specific gravity, maximum dry density, plasticity index, swell potential, and ductility of soil, with a considerable increase in strength (shear, compressive, tensile, and bearing) of the soil. LRHA treatment also improves the durability of soil when subjected to adverse climatic. Furthermore, the study suggests that the brittleness imparted to the soil due to LRHA treatment can be reduced with the inclusion of fiber reinforcement. India is experiencing significant infrastructure development initiatives as a developing nation. Moreover, India is a major producer of lime and paddy which can be utilized in employing LRHA in the stabilization of the problematic soil. The cheap availability of LRHA can help in making the construction work economical and sustainable.