混合骨料粒径级配对充填体早期强度的影响

Influence of Mixed Aggregate Particle Size Gradation on Early Strength of Backfill

为解决金川公司充填骨料不足的问题,进行废石-棒磨砂混合骨料筛分试验及充填体早期强度试验,研究混合骨料粒径特征值和充填体早期强度的变化规律,基于剖面结构分析粒径级配与早期强度的关系。研究结果表明,废石掺量由10%增至40%,混合骨料不均匀系数先减小后增大,曲率系数呈波动式折线变化,加权平均粒径与级配指数均整体呈增大及局部减小趋势;相同条件下,提高质量浓度或胶砂比能够提高充填体早期强度,随废石掺量增加,充填体试块剖面有4个变化阶段,早期强度随废石掺量增大呈先减小后增大又减小的趋势,且废石最优掺量为30%。

In order to solve the problem of insufficient filling aggregate in Jinchuan Company,the screening test of waste stone-rod matte mixed aggregate and the early strength test of backfill were carried out to study the characteristic value of the particle size of the mixed aggregate and the change law of the early strength of the backfill,and the relationship between particle size gradation and early strength was analyzed based on the profile structure.The results show that when the waste rock content increases from 10%to 40%,the uneven coefficient of mixed aggregate first decreases and then increases,the curvature coefficient changes in a wave line,and the weighted average particle size and grading index both increase and decrease.Under the same conditions,the early strength of the backfill can be improved by increasing the mass concentration or the cement sand ratio.With the increase of waste rock content,there are four stages of change in the sample section of the backfill body,the early strength decreases first and then increases and then decreases with the increase of waste rock content,and the optimal waste rock content is 30%.