混合骨料胶结充填体的力学性能及其配比优化设计

Study on Mechanical Properties of Cemented Backfill with Mixed Aggregate and Optimization Design of Proportioning Parameters

针对质量浓度、水泥掺量、粗骨料含量及减水剂掺量4种因素对废石与尾砂混合骨料胶结充填体力学性能的影响,进行正交试验设计。通过对充填体抗压强度、坍落度进行极差分析和方差分析,得到了4种因素的影响程度和显著性影响因素。研究结果表明:质量浓度、粗骨料含量及减水剂掺量为充填料浆坍落度的显著性影响因素,而水泥掺量对充填料浆坍落度无显著影响;粗骨料含量及质量浓度为充填体早期强度的显著性影响因素,而质量浓度及水泥掺量为充填体中后期强度的显著性影响因素;充填体后期抗压强度随粗骨料含量的增加呈先增加后减小的趋势,最佳粗骨料含量为60%;最后就4种因素对混合骨料胶结充填体力学性能的影响进行了机理分析,建立了混合骨料充填体坍落度及抗压强度的回归模型,该模型能够准确预测混合骨料充填体的坍落度和抗压强度的变化规律。由试验结果得出该金属矿山充填料浆配比参数的最佳组合。

Orthogonal test design was carried out to study the effects of mass concentration, cement content, coarse aggregate content and water reducer dosage on the mechanical properties of cemented backfill with mixed aggregate. Through range analysis and variance analysis on compressive strength and slump of backfill, the influence degree and significant influence factors of the four factors were obtained. The results are concluded as follows. Firstly, the mass concentration, coarse aggregate content and water reducer dosage are the significant factors affecting the slump of filling slurry, while the cement content has no significant effect on the slump of filling slurry. Secondly, the content of coarse aggregate and mass concentration are the significant influencing factors for the early strength of backfill, while the mass concentration and cement content are the significant influencing factors for the middle and late strength of backfill. Thirdly, the compressive strength of backfill increases first and then decreases with the increase of coarse aggregate content, and the optimal coarse aggregate content is 60%. Finally, the influencing mechanism of the four factors on the mechanical properties of the cemented backfill with mixed aggregate was analyzed, and the regression models of the slump and compressive strength of the backfill was established. The model can accurately predict the change rule of the slump and compressive strength of the backfill with mixed aggregate. In addition, combining with the experimental results, the optimal proportioning parameters of filling slurry for the metal mine has been obtained.