Use of Sustainable Binders in Soil Stabilization

The procedure of soil treatment with industrial and domestic wastes such as ground glass and coal ash (acting as pozzolans) and carbide lime is a sustainable practice when the assignment involves amendment of the native soil for the production of engineered fills and stabilized bases of pavements. This research assesses the efficiency of sandy soils treated with industrial and domestic residues, demonstrates that the porosity/binder index ($\eta /B_{iv}$) (equivalent to porosity divided by the volumetric content of pozzolan plus carbide lime) performs an essential function in the assessment of the goal blend strength, and proposes a general model that controls the strength-porosity/binder index behavior of sandy soil-pozzolan-lime blends. The controlling parameters evaluated are the amounts of pozzolan and carbide lime, the porosity, and the porosity/binder index. A series of unconfined compression tests was carried out reflecting distinctive amounts of pozzolans, diverse porosities, and discrete carbide lime amounts. The results show that the unconfined compressive strength ($q_u$) increases in a power shape with the reduction of $\eta /B_{iv}$, in which $B_{iv}$ is amended by an exponent (0.28 for the soil-pozzolan-lime blends investigated). For each specific soil, pozzolan, and carbide lime used and each curing period, independent of the amount of binder (herein considered as pozzolan plus carbide lime) and the porosity of the blends, a single correlation is found between $q_u$ and $\eta /{(B_{iv})}^{0.28}$ for the compacted soil–binder mixtures studied herein. The alternative binders studied herein are seen as a sustainable solution for soil stabilization.