不同因素交互作用下胶结充填体力学特性试验研究

Experimental Study on the Mechanical Properties of Cemented Backfill Under the Interaction of Different Factors

针对矿山现场充填料浆堵管和充填体质量差的问题,采用塌落度筒法抗压强度试验和SEM电镜扫描等方法,对不同因素交互作用下充填料浆塌落度、充填体力学特性及充填体微观形貌进行了研究。结果表明:料浆质量浓度对充填料浆塌落度的影响程度远大于灰砂比;随着灰砂比的减小,充填体的抗压强度逐渐减小,灰砂比对充填体抗压强度的影响程度大于质量浓度;料浆质量浓度及灰砂比相同时,废石掺入量存在临界值;料浆质量浓度相同时,养护龄期越短且灰砂比越低,充填体峰后位移量越大,随着龄期增加,充填体内部水化产物逐渐增多,孔隙结构逐渐减少,致密程度逐渐提高。研究成果对提高井下充填体承载能力具有参考价值。

In view of the problems of filling slurry plugging and poor quality of backfill in mine site,the slump cylinder method,compressive strength test,scanning electron microscope and other experimental methods were used to study the slump of filling slurry,the mechanical properties of backfill,and microscopic morphology of the backfill under different factors of interaction.The results are concluded as follows.Firstly,the influence of slurry mass concentration on the slump of filling slurry is much greater than that of cement-sand ratio.Secondly,with the decrease of cement-sand ratio,the compressive strength of backfill decreases gradually,and the influence of cement-sand ratio on the compressive strength of backfill is greater than that of slurry mass concentration.Thirdly,when the slurry mass concentration and cement-sand ratio are the same,there is a critical value for the amount of waste rock.Fourthly,when the slurry mass concentration is the same,the shorter the curing age and the lower the cement-sand ratio,the greater the post-peak displacement of the backfill.As the curing age increases,the hydration products inside the backfill gradually increase,the pore structure gradually decreases,and the compactness gradually increases.The research results have a reference for improving the stable bearing capacity of underground backfill.