摘要
地聚合物-偏高岭土(metakaolin,MK)是一种具有高活性的掺合材料,在一定激发作用下能显现出较好的胶凝性.现将水玻璃(硅酸钠溶液)作为MK的激发剂对珠江三角洲滨海平原一变电站软基进行固化试验,先采取了'水泥+水玻璃'、'水泥+MK'的掺入试验,试验结果表明:水玻璃和MK均能提升水泥土的强度,随着水玻璃掺量的增加水泥土强度呈先增后减趋势,随着MK掺量的增加其增长速率先增大后趋于平缓.在此基础上选其两者优掺范围进行'水泥+水玻璃+MK'的组合掺入试验,发现其固化效果更佳,综合经济和加固效果选出优配组合,并对原状土、纯水泥土与优配组合作渗透试验对比,结果表明优配组合渗透系数最低具有良好的防渗性能,值得在类似工程中推广参考使用.同时借助电镜扫描(SEM)、X射线衍射(XRD)、阳离子交换(CEC)试验、对其固化机理进行分析,并从机制上解释了宏观力学特性变化的现象及原因.
Geopolymer metakaolin(MK)is a highly active mineral admixture,which has good cementitious property under proper excitation.The sodium silicate solution is used as a activator of MK to solidify the soft foundation of a substation in the coastal plain of the Pearl River Delta.The tests of'cement+sodium silicate'and'cement+MK'are carried out respectively.The test results show that sodium silicate and MK can improve the strength of cement soil.With the increase of sodium silicate content,the strength of cement soil increases first and then decreases.With the increase of MK content,the strength growth rate increases first and then tends to be flat.Further selecting the optimum mixing range,the experiment of'cement+sodium silicate+MK'combination mixing is carried out and find that the curing effect is better.Considering the economic and reinforcement effects,the optimum combination is selected to make the permeability tests of undisturbed soil,pure cement soil and optimum combination.The results show that the optimum combination has the lowest permeability coefficient and good impervious performance,which is worthy of popularization and reference in similar projects.At the same time,scanning electron microscopy(SEM),X-ray diffraction(XRD),cation exchange(CEC)tests are used to analyze the curing mechanism,and explain the phenomenon and reason of macroscopical mechanical characteristic change from mechanism.
作者
叶华洋
张伟锋
韦未
董艳林
张婉吟
YE Huayang;ZHANG Weifeng;WEI Wei;DONG Yanlin;ZHANG Wanyin(College of Water Conservancy and Civil Engineering,South China Agricultural University,Guangzhou 510642,China;Zhongshan Power Supply Bureau of Guangdong Power Grid Corporation,Zhongshan 528400,China)
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2019年第4期906-917,共12页
Journal of Basic Science and Engineering
基金
国家级大学生创新训练项目(201710564365)
广东省水利科技创新重点项目(2015-16)
广东电网有限责任公司科技项目(032000KK52160015)
关键词
偏高岭土
水玻璃
软土
组合试验
无侧限抗压强度
机理分析
metakaolin
sodium silicate
soft soil
combination test
unconfined compression strength
micromechanism
