煤矿采空区砂质胶结充填材料特性试验研究

Experimental study on characteristics of arenaceous and cementitious backfill material in goaf of coal mine

利用风积砂作为煤矿采空区充填的骨料与水泥、粉煤灰等混合制成胶结充填材料,通过宏观、细观和微观手段研究该材料的物理力学性质、物质结构和化学反应。结果表明风积砂是一种级配不良骨料,以风积砂为骨料的胶结充填材料,其单轴抗压强度随着水泥和粉煤灰的掺入量升高而增大,但随着初始含水率的增大而减小;胶结充填材料中添加少量石灰可促进其单轴抗压强度的发挥,而添加石膏会抑制其抗压强度的增长。固化后的胶结充填材料压缩破坏过程较短暂,残余强度较低,且存在水泥掺入量下限。

The cementitious backfill materials are made of aggregates,cements,fly ash and so on,eolian sand is taken as the aggregate.The physical and mechanical properties,material strutures and chemical reactions of the materials were researched by macroscopic,microscopic and microcosmic methods.The results show that eolian sand is a kind of poorly graded aggregate,the uniaxial compressive strength of the backfill materials increases with the increase of cements and fly ash,while decreases with the increase of initial water content.Adding a little lime to the backfill materials can increase of the uniaxial compressive strength,while adding gypsum inhibits the increase of compressive strength.The compressing and destruction processes of solidified cementitious backfill materials are short,the residual strength is lower,and there is a lower limit of cements incorporation.