摘要
为了评价淤泥固化土的环境耐久性,采用矿渣体系的碱激发胶凝材料(矿渣粉、偏高岭土、石灰和水玻璃)和普通硅酸盐水泥为固化剂,通过开展无侧限抗压、冻融循环、Na2SO4及NaCl浸泡侵蚀、扫描电镜和EDS-Mapping试验,分析了侵蚀环境下固化淤泥土的典型水化产物、强度演变规律、质量损失率和微观结构特征,结果表明,碱激发固化淤泥内部生成的水化硅铝酸钠凝胶(N-A-S-H)能有效提高强度,但是冻融循环和浸泡侵蚀均会导致固化土强度劣化;水泥固化淤泥受硫酸盐侵蚀后,钙矾石会呈现簇状发展而产生膨胀开裂,导致强度下降;碱激发固化剂的抗氯离子能力优于硫酸根离子,综合环境耐久性优于普通硅酸盐水泥。
In order to evaluate the environmental durability of solidified lake-bottom sediment,alkali activated cementing material of slag system(slag powder,metakaolin,lime and sodium silicate)and traditional cement were used as curing agent.Through unconfined compression,freezing-thawing cycle,Na2SO4 and NaCl erosion leaching,scanning electron microscopy and EDS-Mappingtests,the typical hydrates,strength evolution,mass loss rate and microstructure characteristics of solidified sediment in erosion environment were analyzed.The results show that a large amount of hydrated sodium silicate aluminate gel(N-A-S-H)was formed in the alkali-excited solidified sediment.The freezing-thawing cycle and erosion leaching can lead to the deterioration of the strength of solidified sediment.The development of ettringite led to expansion and cracking when the cement-solidified sediment was eroded by sulfate,which resulted in the decrease of strength.The alkali-activated curing agent has better chloride ion resistance than sulfate ion and better comprehensive environmental durability than conventional Portland cement.
作者
王矿山
庞龙
戴振鑫
章晖
张新军
Wang Kuangshan;Pang Long;Dai Zhenxin;Zhang Hui;Zhang Xinjun(PowerChina Huadong Survey,Design and Research Institute Co.,Ltd.,Hangzhou 310000,Zhejiang,China;China Railway First Bureau Group Co.,Ltd.,Xi’an 710000,Shaanxi,China)
出处
《岩土工程技术》
2023年第4期455-460,共6页
Geotechnical Engineering Technique
基金
安徽省高校自然科学研究重点项目(2022AH051388,KY2020-ZX-24)。
关键词
固化淤泥
强度
冻融循环
侵蚀
耐久性
solidified sediment
strength
freezing-thawing cycle
erosion
durability
