ABSTRACT

The influence of underground humidity on the mechanical performance of cemented paste backfill (CPB) in metal mines is a problem that cannot be ignored. To this end, this paper conducted the curing experiments of CPB samples under different curing humidity (60%, 80% and 95%). Physical properties such as moisture content and dry density as well as mechanical properties such as uniaxial compressive strength, cohesion and internal friction angle of the CPB samples were monitored during fixed curing time (3, 7, 14 and 28 days). TGA/DTG, XRD and SEM were used to analyse the microstructure of CPB samples under different curing humidity at 3 and 28 days, and a BP neural network prediction model of CPB strength was established based on the obtained data. The results show that the curing humidity has a great influence on the physical and mechanical properties of the paste, and the amount of hydration products and the change of pore structure are the main reasons that affect the properties. In order to ensure the safety and economy of the CPB structure, the influence of environmental humidity on the paste should be considered in the filling design.

摘要

地下湿度对金属矿山胶结膏充填体（CPB）力学性能的影响是一个不容忽视的问题。为此，本文对CPB样品在不同固化湿度（60%、80%和95%）下进行了固化实验。在固定固化时间（3、7、14 和 28 天）内监测 CPB 样品的物理性能（如含水量和干密度）以及机械性能（如单轴抗压强度、内聚力和内摩擦角）。利用TGA/DTG、XRD和SEM对不同养护湿度下CPB样品在3和28 d的微观结构进行了分析，并根据获得的数据建立了CPB强度的BP神经网络预测模型。结果表明，固化湿度对糊体的物理机械性能影响较大，而水化产物的量和孔结构的变化是影响性能的主要原因。为了保证CPB结构的安全性和经济性，在填充设计时应考虑环境湿度对膏体的影响。