Self-desiccation behavior of nano-cemented tailings backfill plug: Insights from thermo-mechanical-chemical column experiments

Abstract

This paper examines the influence of various factors, including the addition of nano-calcium carbonate particles (chemical processes, C) to CPBs, non-isothermal field curing temperatures (thermal factor, T), and field vertical curing stress (mechanical factor, M), on the self-desiccation capacity of CPB plugs. The assessment of self-desiccation involves the determination of pore water pressure (PWP) and volumetric water content (VWC) in the examined CPBs. Thermo-mechanical-chemical (TMC) column experiments were conducted to investigate the interaction among these factors and their collective impact on the evolution of PWP and VWC within the CPB plug. The findings underscore that each factor, both individually and in combination, significantly affects the magnitude and progression of self-desiccation in CPB plugs. Notably, the factors of elevated field temperature and the introduction of nano-calcium carbonate (NC) to the CPB exert the most substantial influence on the extent and enhancement of self-desiccation, whereas the impact of field curing stress in isolation is comparatively much weaker. The integration of nano-calcium carbonate, especially under non-isothermal conditions and concurrent field stress, emerges as a key contributor to enhanced PWP and VWC dissipation rates. The role of non-isothermal field curing temperature is underscored as a significant contributing factor in the self-desiccation of CPB plugs. The results presented in this paper will contribute to a more cost-effective design of CPB plugs and the improved optimization of CPB mixtures with nano-calcium carbonate particles.