改性水玻璃固化盐渍土强度及冻融循环耐久性试验研究

吕擎峰; 孟惠芳; 王生新; 章清; 陈辉

doi:10.11936/bjutxb2016070045

改性水玻璃固化盐渍土强度及冻融循环耐久性试验研究

doi: 10.11936/bjutxb2016070045

1.
兰州大学西部灾害与环境力学教育部重点实验室, 兰州 730000
2.
甘肃省科学院地质自然灾害防治研究所, 兰州 730000

基金项目: 国家自然科学基金资助项目(51469001)

详细信息

作者简介:
作者简介: 吕擎峰(1971—), 男, 副教授, 主要从事岩土工程方面的研究, E-mail:lvqf@lzu.edu.cn

中图分类号: TU443
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出版历程
- 收稿日期: 2016-07-17
- 网络出版日期: 2022-09-09
- 刊出日期: 2017-01-01

Research of Strength and Freezing-thawing Durability of Saline Soil Solidified by Modified Sodium Silicate

1.
Key Laboratory of Mechanics on Western Disaster and Environment Mechanics, Lanzhou University, Lanzhou 730000, China
2.
Geological Hazards Research and Prevention Institute, Gansu Academy of Sciences, Lanzhou 730000, China

摘要

摘要: 为了解决盐渍土盐胀和溶陷等不良工程问题,进行了20、40、60℃改性水玻璃碱激发粉煤灰固化盐渍土试验研究. 通过冻融循环试验、无侧限抗压强度试验、X射线衍射光谱以及微观结构测试,研究了温度改性水玻璃固化盐渍土的强度和冻融循环耐久性. 结果表明:改性水玻璃固化盐渍土的强度随温度的升高反而降低;不同温度改性的水玻璃固化盐渍土的抗压强度随冻融循环次数的增加而降低并在冻融10次以后下降幅度减小;不同温度改性水玻璃固化盐渍土没有新的晶体衍射峰出现,随着改性温度的升高,芒硝和白云石的衍射强度增大,表观小孔隙率变大,强度降低,冻融循环后,微观结构遭到破坏.
- 改性水玻璃 /
- 盐渍土 /
- 固化 /
- 冻融循环 /
- 强度
Abstract: In order to solve relevant engineering problems about sulphate salty soil and the collapsibility of saline, research of saline soil solidified by coal ash which was stimulated by temperature modification sodium silicate, was conducted in this paper. Strength and freezing-thawing durability of saline soil solidified by sodium silicate modified by temperature were studied by means of freeze-thaw cycle test, unconfined compressive strength test, X-ray diffraction spectra and microstructure test. The result shows that the strength of saline soil solidified by modified sodium silicate decreases against the rise of temperature. The shear strength of saline soil solidified by sodium silicate which is modified under different temperature decreases while the times of freeze-thaw cycle tests increase and its decreasing range is lessen after 10 times. There is no appearance of new crystal materials in saline soil solidified by sodium silicate modified by temperature. With the increasing of modification temperature, the diffracted intensity of mirabilite and dolomite gets enhanced, the apparent porosity becomes bigger, and strength decreases. The microstructure is damaged after freeze-thaw cycle tests.
- modified sodium silicate /
- saline soil /
- solidification /
- freeze-thaw cycles /
- strength
The authors have declared that no competing interests exist.

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图 1 固化土抗压强度和改性水玻璃温度的关系

Figure 1. Relationships between com pressive strength of solidified soil and sodium silicate density

下载: 全尺寸图片幻灯片

图 2 不同改性温度固化盐渍土的单轴应力-应变曲线

Figure 2. Stress-strain curve of saline soil solidified by sodium silicate modified under different temperature

下载: 全尺寸图片幻灯片

图 3 不同改性温度水玻璃固化盐渍土冻融循环后无侧限抗压强度

Figure 3. Strength of saline soil samples solidified with sodium silicate in different modified temperatures after freeze-thaw cycle

下载: 全尺寸图片幻灯片

图 4 不同改性温度固化盐渍土的X衍射谱图

Figure 4. X-ray spectra of saline soil solidified with sodium silicate in different modified temperatures

下载: 全尺寸图片幻灯片

图 5 不同固化温度下20°Bé水玻璃固化盐渍土冻融循环后试样的SEM图像

Figure 5. SEM photograph of saline soil samples solidified with 20°Bé sodium silicate in different temperatures modified after freeze-thaw cycles

下载: 全尺寸图片幻灯片

表 1 土中离子组成状况

Table 1. State of ion composition in soil

项目		盐渍土	7%石灰+14%粉煤灰+20°Bé水玻璃
	C $\begin{matrix} O_{3}^{2 -} \end{matrix}$	68	64
阴离子质量分数/	HC $\begin{matrix} O_{3}^{-} \end{matrix}$	414	2838
(mg·kg^-1)	S $\begin{matrix} O_{4}^{2 -} \end{matrix}$	25840	8213
	Cl^-	25413	28419
阳离子质量分数/	Ca²⁺	4077	1597
(mg·kg^-1)	Mg²⁺	4968	1110
	Na⁺+K⁺	15732	19519

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