Moisture

Engineering

Organic matter

Curing (chemistry)

Soil stabilization

Geotechnical engineering

Metallurgy

Materials science

Sulfate

Chemical engineering

Geology

Soil water

Shrinkage

Pozzolan

Organic chemistry

Portland cement

Cement

Lime

Environmental science

Fly ash

Soil science

Composite material

Compaction

Chemistry

Water content

Pozzolanic reaction

Expansive clay

Journal of Rock Mechanics and Geotechnical Engineering

Volume instability of expansive soils due to moisture fluctuations is often disastrous, causing severe damages and distortions in the supported structures. It is, therefore, necessary to adequately improve the performance of such soils that they can favorably fulfil the post-construction stability requirements. This can be achieved through chemical stabilization using additives such as lime, cement and fly ash. In this paper, suitability of such additives under various conditions and their mechanisms are reviewed in detail. It is observed that the stabilization process primarily involves hydration, cation exchange, flocculation and pozzolanic reactions. The degree of stabilization is controlled by several factors such as additive type, additive content, soil type, soil mineralogy, curing period, curing temperature, delay in compaction, pH of soil matrix, and molding water content, including presence of nano-silica, organic matter and sulfate compounds. Provision of nano-silica not only improves soil packing but also accelerates the pozzolanic reaction. However, presence of deleterious compounds such as sulfate or organic matter can turn the treated soils unfavorable at times even worser than the unstabilized ones.

Stabilization of expansive soils using chemical additives: A review