不同改良剂膨胀土性能试验与对比分析

Performance Test and Comparative Analysis of Expansive Soil with Different Improvers

为了探究生产生活废弃物对膨胀土的改良效果,提高资源利用率,制作了不同掺量下的水泥、蛋壳粉、铜尾矿砂、锯末改良膨胀土试件,通过开展直剪试验、固结试验、界限含水率试验、自由膨胀率试验和标准吸湿含水率试验,评价改良效果,得出主要结论为:四种改良剂均对膨胀土有改良作用,整体来看,随着掺量增大,改良土粘聚力、摩擦角、压缩模量增大,塑性指数、标准吸湿含水率、自由膨胀率减小;综合考虑改良效果及成本,水泥、铜尾矿砂、蛋壳粉、锯末的推荐用量分别为4%、8%、6%、4%。

In order to explore the improvement effect of production and household waste on the expansive soil and improve the resource utilization rate,test specimens of improved expansive soil with different mixing amounts of cement,eggshell powder,copper tailing sand,and sawdust are made.The improvement effects are evaluated by carrying out the direct shear tests,consolidation tests,boundary moisture content tests,free expansion rate tests,and standard moisture absorption rate tests.The main conclusions are as follows:four kinds of improvers have the improving effect on the expansive soil.As a whole,with the increase of the mixing amount,the cohesion,friction angle,compression modulus of the improved soil increase,while the plasticity index,standard moisture absorption and moisture content,and free expansion rate decrease.Through the overall consideration of the improvement effect and cost,the recommended amounts for cement,copper tailing sand,eggshell powder,and sawdust are respectively 4%,8%,6%,and 4%.