稻壳灰固化红黏土的路用性能及微观机理

Road Performance and Micro Mechanism of Rice Husk Ash Modified Red Clay

为响应建设节约的发展思路,向红黏土中掺入稻壳灰,并通过一系列实验探讨稻壳灰对红黏土力学性能的影响,分析稻壳灰对红黏土的微观作用机理。试验结果表明,掺入稻壳灰后红黏土液塑限变化较小;其最优含水率与渗透系数随稻壳灰掺量的增加而增高,最大干密度降低;掺入稻壳灰的红黏土抗压强度随掺量的增加呈先增后减的趋势,当稻壳灰掺入量为15%,养护时间为28 d时达到最大值。电镜扫描试验发现:稻壳灰表面覆盖大量的胶凝物质,红黏土结构密实性相应提升。用稻壳灰改良红黏土能节约路基的建设成本,同时也有利于保护环境,实现资源的可持续利用。

In response to the development idea of construction saving, rice husk ash is filled into red clay. The effect of rice husk ash on the road performance and micro mechanism of red clay is studied through a series of experiments. The results showed that the liquid plastic limit of red clay changed little with the addition of rice husk ash, the maximum dry density decreased with the increase of rice husk ash, and the optimal moisture content increased. The compressive strength of red clay mixed with rice husk ash increased first and then decreased with the increase of the content, and reached the maximum when the content was 15% and the curing time was 28 days. SEM test showed that the structural compactness of solidified red clay was improved, and in this process cementitious materials were produced. Using rice husk ash to improve red clay could be cost-effective in respect to roadbed stability, and can be beneficial in protecting the environment and realizing sustainable use of resources.