尾砂胶结充填体力学性能与微观结构研究

Study on mechanical properties and microstructure of the cemented tailings backfill

胶凝材料水化产物的种类、数量及其微观结构将直接影响尾砂胶结充填体的宏观力学性能。本文采用XRD、TG-DSC、SEM等研究方法,建立了尾砂胶结充填体宏观力学性能(单轴抗压强度)与胶凝材料水化产物种类和数量之间的关系。研究结果表明,随着灰砂比和养护龄期的增长,尾砂胶结充填体内钙矾石等水化产物的含量随之增多,尾砂胶结充填体的单轴抗压强度σc与胶结体中钙矾石的含量x呈一次直线正相关关系,即σc=2.0126x+0.5295,相关性系数为0.9610;增加充填体中AFt的含量有助于提高其单轴抗压强度。

The macro-mechanical properties of cemented tailings backfill were affected directly by the kind and quantity of hydration products of cementitious materials and its microstructure.By means of XRD,TG-DSC,SEM,the relationships between macro-mechanical properties of cemented tailings backfill and the kind and quantity of hydration products were set in this paper.The results showed that the quantities of hydration products in cemented tailings backfill such as ettringite（AFt）was increased with cement-sand ratios and curing period,and the uniaxial compressive strengthσcof cemented tailings backfill had a linear correlation with the quantities of AFt-x.The arithmetic expression isσc=2.0126x＋0.5295,and its relative coefficience is 0.9610.Increasing the quantities of AFt can be helpful to improve the uniaxial compressive strength of cemented tailings backfill.