碱激发材料加固软土强度的影响因素试验研究  

Experimental Study on Factors Affecting Strength of Soft Soil Stabilized with Alkali-activated Material

作　　者：朱月 陈锐 ZHU Yue;CHEN Rui(School of Highway,Chang’an University,Xi’an 710064,China)

机构地区：[1]长安大学公路学院,西安市710064

出　　处：《公路》2020年第3期23-28,共6页Highway

基　　金：陕西省自然科学基础研究计划项目,项目编号2018JQ5001。

摘　　要：采用无侧限抗压强度试验和电镜扫描分析,系统研究了影响碱激发材料加固软土强度的因素(掺入比、龄期、粉料配比、NaOH浓度和含水率),探讨了加固土强度随龄期的增长规律和加固机理。试验结果表明:掺入比、龄期和含水率对碱激发材料加固土强度均有显著影响,粉料配比对强度的影响次之,而NaOH浓度对强度的影响不明显;碱激发材料加固软土的强度随龄期的增大而增大,随掺入比的增大呈先增大后略微减小的趋势;碱激发材料加固软土的强度随含水率的减小显著增大,其强度与含水率呈对数函数关系。根据试验数据建立了碱激发材料加固土的强度随龄期增长的预测模型。电镜扫描结果表明碱激发材料的水化产物填充在土颗粒孔隙中并起到胶结作用,使土的微观结构更加密实,进而提高了土体强度。Unconfined compressive strength tests and scanning electron microscopy(SEM)imaging are conducted to clarify the factors(including concentration of alkali-activated material(AAM),curing age,proportion of raw material,concentration of NaOH and water content)which affect strength of soft soil stabilized with AAM.The experimental results show that concentration of additive,curing age,and water content has significant effect on strength development of AAM stabilized soil,proportion of raw material has minor effect and concentration of NaOH has minor effect on the strength of the stabilized soil.The strength of stabilized soil increases with curing age,and it first increases with concentration of AAM up to certain point and then slightly decreases.The strength of stabilized soil increases with decreasing water content and the relation between strength of stabilized soil and water content can be described using logarithm function.A prediction model is proposed based on available experimental data for predicting the strength growing of AAM stabilized soil with curing age.The SEM analysis shows that the hydrated products of AAM fill the voids between soil particles and cement them together,leading to a dense microstructure and hence enhanced compressive strength.

关 键 词：软土加固 碱激发材料 无侧限抗压强度 影响因素 电镜扫描 

分 类 号：U416.1[交通运输工程—道路与铁道工程]