Chemical Basis of Soil Stabilisation

Stabilisation of soil using chemical binders has been studied and has been used extensively in various civil engineering works since the 1970s. These include road and highway construction, stabilisation of marginal land with soft and contaminated soils, land fill and reclamation as well as excavations and underground construction. The chemicals that are most widely used include cement, lime, fly ash, ground granulated blast furnace slag (GGBS). Other binders and binder components include sulphoaluminate cement (e.g. Chen et al. 2020 ), gypsum (e.g. Zhu et al. 2018 ; Chen et al. 2018 , 2020 ; He et al. 2021 ), cement kiln dust (e.g. Miller and Zaman 2000 ), bentonite (e.g. Katsioti et al. 2008 ; Lin et al. 2009 ) and mining waste products such as jarosite and alunite (e.g. Boura et al. 2003 ; Katsioti et al. 2009 ). Some of these are used as components in a cocktail of binders. Additives are sometimes required to predispose the conditions to initiate as well as to balance the stoichiometry for the hardening reactions. Non-cementitious binders such as asphaltic emulsion ( Lucena et al. 2014 ) have also been studied. However, as they have not been used on a wide scale, they will not be discussed herein.