Improving soil properties by adding stabilizing materials, such as cement, has garnered significant attention from researchers, particularly for enhancing soils often deemed poor geotechnical quality. This approach becomes even more advantageous when applied to increase the stability of mining tailings deposits and ensure environmental safety. This study investigates the effects of cement addition and dry density on the strength and durability of compacted bauxite tailings-cement blends. The porosity/cement index, widely used in soil-cement mixture research, was adopted to analyze the parameters that control the strength and durability of these blends. Results demonstrate that increasing cement content and dry density significantly improves unconfined compressive strength (qu) and reduces accumulated mass loss (ALM) during wet/dry cycles. The porosity/cement index effectively describes the variations in qu and ALM, as expressed by an empirical equation, which can be highly beneficial for the practical application of treated mining tailings as construction materials.

The incorporation of cement to improve soil properties and attract the re-use of locally available materials has become a part of current geotechnical engineering projects. Its applicability varies from construction of pavement base layers, slope protection for earth dams, to support layer for shallow foundations. Unconfined behaviour might be used to evaluate the basic mechanical properties and efficiency of the cemented soils. The proposed relationship between porosity (eta) and volumetric cement content (C-iv), presented as porosity cement index (eta/C-iv), was shown to play an important role in the initial shear stiffness (G(0)), tensile (q(t)) and compressive (q(u)) strength of cemented materials. This research aims to assess these parameters through experimental investigation and modelling predictions. Bender elements testing were carried out to assess the maximum initial shear stiffness (G(0)) prior to specimens testing, and assessing G(0) evolution during cement hydration, focusing on the anisotropic/isotropic behaviour established during specimen moulding. Results show a good correlation between experimental and numerical data. It was also observed that cementation isotropises G(0) during curing.