In aggressive environments, including acidic environments, low and high-plasticity clays play an important role in transmitting and spreading dangerous pollution. Stabilisation of these types of soils can improve their characteristics. In this research, different ratios of two precursors with a low calcium percentage, for example, waste statiti-ceramic sphere powder (WS-CSP) and a high calcium percentage (e.g. ground granulated blast furnace slag [GGBFS], were employed to investigate the properties of soils with different plasticity indices [PIs]). Low and high-plasticity-stabilised and stabilised with 5 wt% Portland cement specimens were prepared and exposed to an acidic solution with a pH of 2.5 in intervals of 1, 3, 6 and 9 months. The long-term durability of specimens was evaluated using the uniaxial compressive strength test (UCS) and bending strength test (BS). Additionally, the microstructures of these specimens under various time intervals were analyzed using scanning electron microscopy and Fourier-transform infrared. According to the results, in an acidic environment, the reduction in UCS, BS, toughness and secant modulus of elasticity (E50) for low-plasticity-stabilised specimens and containing 100% WS-CSP was lower than that of other specimens. The Taguchi method and ANOVA were used to investigate the effect of each control factor on the UCS and BS.

Utilizing casein in geotechnical engineering and construction can reduce global dairy waste. Variations in initial water content during sample preparation influence cation and OH ion availability, alkaline additive concentrations, casein binder function, and rheological properties of the casein solution. This study investigates the impact of initial water content and casein solution rheology on unconfined compressive strength in two soil types (coarse and fine) treated with casein, both in dry conditions and after water immersion. The study also assesses the long-term performance of casein-treated soil under bio-decomposition. Results suggest that increasing casein content, beyond the optimal ratio, can enhance strength by adjusting initial water concentration. Notably, calcium caseinate-treated soil shows improved water resistance, with wet strength reaching 833 kPa at 5% casein and 20% initial water content, due to reduced viscosity and better workability, resulting in a more rigid soil structure during preparation. We propose an empirical formula describing the influence of casein solution rheological characteristics on soil strength. Furthermore, artificial neural networks, developed from experimental data, predict casein-treated soil strength, highlighting the significance of initial water content and rheological parameters.