水泥改良膨胀土强度特性试验研究  

Research on Strength Characteristics of Cement Modified Expansive Soil

作　　者：高建伟[1] 余宏明[1] 钱玉智[1] 李科[1] 

机构地区：[1]中国地质大学工程学院,武汉市430074

出　　处：《公路》2013年第12期165-168,共4页Highway

基　　金：国家自然科学基金;项目编号41272377

摘　　要：巴东组紫红色泥岩风化物具有膨胀性,不能满足路基的要求,利用水泥对路基填料进行改良,并通过对击实试验、无侧限抗压强度试验、CBR试验和电子显微镜扫描试验的分析,研究水泥改良土在不同水泥配比下的物理力学指标。结果表明:随着水泥配比的增加,改良土的CBR2.5和CBR5.0呈线性增加趋势,改良土的膨胀性得到显著改善。同时试验表明,水泥改良土具有良好的水稳定性。此外,改良土的无侧限抗压强度亦随水泥配比的增加而线性增加。改良土微观结构表明,改良土宏观性质的大幅度提升是由于改良土孔隙中生成了大量纤维状钙矾石,提高了土颗粒黏聚力,从而改善土体性质。The weathered material of red mudstone of Badong has expansion properties, hence cannot meet the requirement of roadbed, so cement is used to modify the roadbed fillings. Physical and mechanical indexes of cement modified soil under different cement ratio are studied through compaction test, unconfined compression strength, CBR and SEM to provide a reference for roadbed construction. The results show that CBR2.5 and CBR5.0 are linearly increasing along with the increase of cement ratio, the expansion of modified soil is significantly reduced. At the same time the test indicates cement modified soil has good water stability. In addition, unconfined compression strength of modified soil also linearly increases with the increase of cement ratio. The microstructure of modified soil indicates that crystallization of fibrous ettringite greatly enhance the macroscopic properties, and improve the cohesive force of soil particles,so as to the soil properties.

关 键 词：水泥改良 膨胀土 CBR 无侧限抗压 微观结构 

分 类 号：U416.167[交通运输工程—道路与铁道工程]