Advanced tools for analyzing and predicting the performance and durability of paste backfill under different thermal conditions

胶结膏体充填(CPB)是一种尾矿、粘结剂和水的混合物，在采矿业中广泛使用。它的主要目的是确保地下巷道的稳定性，安全和最大限度地回收矿石，并为潜在的产酸尾矿提供一种环境友好的地下处置手段。然而，许多基本方面，如温度对性能(机械稳定性、CPB质量)和耐久性(抗硫酸盐侵蚀：硫酸盐侵蚀粘结剂并破坏其结合效果)性能的影响仍然知之甚少。此外，众所周知，在广泛的工程问题中，材料性能的变化和损伤的积累不仅是由机械载荷引起的，也是由温度和湿度引起的载荷以及化学侵蚀因素(如硫酸盐)或这些过程的各种组合引起的。然而，关于CPB中热、化学、氢气和机械过程之间相互作用的知识水平仍然非常有限。因此，要准确预测CPB的性能和耐久性能，需要深入了解温度对这些性能的影响，以及CPB中发生的热-化学-力学(TCHM)耦合机制，以及预测它们的工具的开发。因此，通过实验和建模技术的结合，本研究计划将集中于以下目标：(I)了解温度和耦合TCHM载荷对CPB性能和耐久性能的影响；(Ii)开发和验证先进的优化工具，从而有可能为任何养护温度制备最优的CPB配方；以及(Iii)开发和验证先进的TCHM模型，以预测CPB在不同TCHM载荷条件下的机械稳定性和耐久性。这项拟议的研究将为可持续和安全的采矿提供基础知识和先进的工具或技术，从而使研究界、采矿业、教育机构、土木工程公司和加拿大社区受益。

Cemented paste backfill (CPB), a mix of tailings, binder and water, is extensively used in the mining industry. Its main purpose is to ensure the stability of underground openings, safe and maximum ore recovery, and also to provide an environmental-friendly means of underground disposal of potential acid generating tailings. However, many fundamental aspects, such as the impact of temperature on the performance (mechanical stability, quality of the CPB) and durability (resistance to sulphate attack: sulphate attacks the binder and destroys its binding effect) properties are still poorly understood. Furthermore, it is well known that in a broad range of engineering problems the change of material properties and accumulation of damage are not only caused by mechanical loads, but also by temperature and moisture induced loading as well as chemically aggressive factors (e.g., sulphate) or various combinations of these processes. However, the level of knowledge on these interactions between thermal, chemical, hydric and mechanical processes in CPB is still very limited. Thus, an accurate prediction of the performance and durability properties of CPB needs a deep understanding of the effect of temperature on these properties and of the coupled thermo-chemo-hydric-mechanical (TCHM) mechanisms that occur in CPB, and the development of tools that will predict them. Hence, through the combination of experimental and modeling techniques, this research program will focus on the following objectives: (i) understand the impact of temperature and coupled TCHM loadings on the performance and durability properties of CPB; (ii) develop and validate advanced optimization tools that will make it possible to prepare optimal CPB recipes for any curing temperature; and (iii) develop and validate advanced TCHM models to predict the mechanical stability and the durability of CPB under various TCHM loading conditions. This proposed research will benefit the research community, mining industry, educational institutions, civil engineering firms, and Canadian community by providing of fundamental knowledge and advanced tools or techniques for sustainable and safe mining.