掺入粉煤灰对水泥土强度影响试验分析

Experimental Analysis of Influence of Fly Ash on Strength of Cement Soil

以取自广州南沙的软粘土为研究对象,通过抗压试验与电镜扫描研究了粉煤灰掺量对不同养护龄期的水泥土无侧限抗压强度的影响,粉煤灰掺量分别为6%,8%,15%,25%,养护龄期分别为7 d,14 d,28 d,90 d。试验结果表明:掺入粉煤灰对提高水泥土早期强度作用不明显;水泥土强度随粉煤灰掺量的增加先增大后减小,最优掺量为15%,此时水泥土强度最高;从微观结构角度定性揭示了掺入粉煤灰的水泥土强度发展机理,并验证了上述强度试验结果。研究结果可为地基处理中水泥加固土的设计及施工提供参考。

Taking the soft clay from Nansha,Guangzhou as the research object,the influence of fly ash content on the unconfined compressive strength of cement soil in different curing age was studied by compression test and scanning electron microscope.The content of fly ash was 6%,8%,15%,25%respectively,and the curing age was 7 d,14 d,28 d,90 d respectively.The test results show that:the effect of adding fly ash on the early strength of cement soil is not obvious;the strength of cement soil first increases and then decreases with the increase of fly ash content,and the optimal content is 15%,at this time,the strength of cement soil is the highest;the development mechanism of strength of cement soil mixed with fly ash is qualitatively revealed from the perspective of microstructure,and the above strength test results are verified.The research results can provide reference for the design and construction of cement stabilized soil in foundation treatment.