粒化高炉矿渣微粉固化淤泥质土的动力特性及微观机理

硅酸盐通报 ›› 2021, Vol. 40 ›› Issue (7): 2306-2312.

粒化高炉矿渣微粉固化淤泥质土的动力特性及微观机理

乔京生^1,2, 王旭影^1,2, 王冠泓³, 赵建业⁴

1.唐山学院土木工程学院,唐山 063000;
2.唐山市复杂岩土与工业废渣再生利用重点实验室,唐山 063000;
3.中国建筑科学研究院,北京 100013;
4.河北省地矿局第五地质大队,唐山 063000

收稿日期:2021-02-02 修回日期:2021-03-08 出版日期:2021-07-15 发布日期:2021-08-04
通讯作者: 王旭影,博士,讲师。E-mail:wxy87121@126.com
作者简介:乔京生(1968—),男,博士,教授。主要从事地基与基础工程方面的研究。E-mail:qjs99@sohu.com
基金资助:
唐山市钢渣混合料应用研究基础创新团队(18130217A);河北省高等学校科学技术研究项目(BJ2020204,QN2021319);唐山市科技计划项目(20130223b)

Dynamic Characteristics and Microscopic Mechanism of Muddy Clay Solidified by Ground Granulated Blast-Furnace Slag

QIAO Jingsheng^1,2, WANG Xuying^1,2, WANG Guanhong³, ZHAO Jianye⁴

1. Civil Engineering College, Tangshan University, Tangshan 063000, China;
2. Tangshan Key Laboratory of Complex Geotechnical and Industrial Waste Recycling, Tangshan 063000, China;
3. China Academy of Building Research, Beijing 100013, China;
4. The Fifth Geology Company of Hebei Geology & Minerals Bureau, Tangshan 063000, China

Received:2021-02-02 Revised:2021-03-08 Online:2021-07-15 Published:2021-08-04

摘要/Abstract

摘要： 采用不同掺量的粒化高炉矿渣微粉(GGBS)对淤泥质土进行固化处理,利用动三轴试验,确定GGBS的最优掺量,并分析最优掺量固化土在不同围压下的动强度、动弹性模量和动阻尼比的变化规律,最后利用SEM和EDS分析固化土的微观结构和元素变化,揭示其固化机理。结果表明,当GGBS掺量为20%(质量分数,下同)时,固化土动强度呈台阶式增大,20%为最优掺量。20%掺量固化土动强度是淤泥质土的2～4倍,增大45～60 kPa,动弹性模量最大值是淤泥质土的3~4倍,动阻尼比相对减小,100 kPa和150 kPa围压下动阻尼比减小尤为明显。SEM照片显示,20%GGBS掺量的固化土颗粒成团聚状,颗粒间的孔隙大大降低,土体变得相对致密。EDS能谱显示,大量的Ca²⁺发生离子交换团粒化作用,从而增强了土颗粒之间的结合力,土颗粒的内摩擦角变大,土体的强度也随之提高。

关键词: 淤泥质土, 粒化高炉矿渣微粉, 固化, 动力特性, 微观机理, 动三轴试验

Abstract: Different content of ground granulated blast-furnace slag (GGBS) was used to solidify the muddy clay. The dynamic triaxial test was used to determine the optimal amount of GGBS, and the dynamic strength, dynamic elastic modulus, and dynamic damping ratio of the solidified clay with the optimal amount of GGBS under different confining pressures were analyzed. Finally, SEM test and XRD test were used to analyze the microstructure and composition changes of GGBS solidified clay, and its solidification mechanism was revealed. The results show that when the mixing amount of GGBS is 20% (mass fraction, the same bellow), the dynamic strength of GGBS solidified clay increases stepwise, and 20% is the optimal mixing amount of GGBS. The dynamic strength of 20% GGBS solidified clay is 2 times to 4 times that of the muddy clay, increasing by 45 kPa to 60 kPa, and the maximum dynamic elastic modulus is 3 times to 4 times that of the muddy clay, and the dynamic damping ratio is relatively reduced. Especially under the confining pressure of 100 kPa and 150 kPa, the dynamic damping ratio decreases significantly. The SEM images show that the solidified soil particles with 20% GGBS become agglomerated, the pores between the particles are greatly reduced, and the soil becomes relatively dense. The EDS patterns show that a large amount of Ca²⁺ undergoes ion exchange and granulation, thereby enhancing the binding force between soil particles. The internal friction angle of the clay particles becomes larger, and the strength of the clay body is also improved.

Key words: muddy clay, ground granulated blast-furnace slag, solidification, dynamic characteristic, microscopic mechanism, dynamic triaxial test

中图分类号:

TU435

乔京生, 王旭影, 王冠泓, 赵建业. 粒化高炉矿渣微粉固化淤泥质土的动力特性及微观机理[J]. 硅酸盐通报, 2021, 40(7): 2306-2312.

QIAO Jingsheng, WANG Xuying, WANG Guanhong, ZHAO Jianye. Dynamic Characteristics and Microscopic Mechanism of Muddy Clay Solidified by Ground Granulated Blast-Furnace Slag[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(7): 2306-2312.

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