Dynamic stress and microanalyses of the cement-soil modified by nano-SiO2 in the seawater corrosive environment
-
摘要:
为研究纳米SiO2改良水泥土抵抗动力荷载-海水腐蚀耦合作用效果，通过动三轴、扫描电镜（SEM）、核磁共振试验（NMR），获取不同海盐溶液浓度和时间下动应力参数及NMR曲线图、SEM图，探究海盐溶液浓度和腐蚀天数对改良前后水泥土的影响。试验结果表明：改良土内部孔隙减少，土颗粒间胶结度提高，土体抵抗动力荷载-海水腐蚀耦合作用能力增强，清水环境下，养护7，14，28 d改良水泥土动强度分别提高了4.8%、6.6%、7.3%；经海水腐蚀后，土体内部结构遭到破坏，土颗粒松动且孔隙增多，水泥土动强度明显下降，腐蚀28 d、清水、1倍、2倍、3倍海水浓度溶液环境下，纳米水泥土相对于普通水泥土动强度分别提高了9.4%、7.3%、6.6%、6.3%。
Abstract:In order to study the coupling effect of nano-SiO2 modified cement soil against dynamic load and seawater corrosion, dynamic stress parameters, NMR curves and SEM diagrams under different sea salt solution concentrations and times are obtained through the dynamic triaxial, scanning electron microscope and nuclear magnetic resonance tests to explore the effects of sea salt solution concentrations and corrosion days on the cement soil before and after improvement. The test results show that the internal pores of the improved soil are reduced, the cementation between the soil particles is improved, and the soil's ability to resist the coupling action of dynamic load and seawater corrosion is enhanced. Under the clear water environment, the dynamic strength of the improved cement soil after curing for 7, 14 and 28 days is increased by 4.8%, 6.6% and 7.3%, respectively. After sea water corrosion, the internal structure of soil is damaged, soil particles become loose and pores increased, and the dynamic strength of the cement soil decreases significantly. After 28 days of corrosion, the dynamic strength of the nano cement soil is increased by 9.4%, 7.3%, 6.6% and 6.3%, respectively, compared with the ordinary cement soil under the environment of clean water, double and triple seawater concentration solution.
-
Key words:
- nano-SiO2 /
- cement soil /
- dynamic triaxial /
- dynamic strength /
- corrosive environment
-
-
表 1 试验用土基本物理指标
Table 1. Properties of the tested soil
密度/
（g∙cm−3）比重 孔隙
比液限/
%塑限/
%塑性
指数压缩系数/
（MPa−1）1.6 2.68 1.15 39.44 19.45 19.99 1.45 
下载: 导出CSV
表 2 纳米SiO2的主要性能指标
Table 2. Properties of nano silicon powder
粒径
/nm比表面积
/（m2∙g−1）表面羟
基/%摇实密度
/（g∙cm−3）松装密度
/（g∙cm−3）sio2−x含
量/%密度
/（g∙cm−3）10±5 640±50 48 <0.22 <0.15 >99.9 2.44
下载: 导出CSV
表 3 试验配比方案
Table 3. Test matching scheme
水泥掺量(m水泥/m湿土×100%） 15% 纳米SiO2掺量（aw＝ 
/m湿土×100%）0%，2.5% 水灰比（w/c=m水 /( 
+ m水泥)）0.45 海盐浓度/（g·L−1） 0，35，70，105
下载: 导出CSV
-
[1] 何开胜. 水泥土搅拌桩的施工质量问题和解决方法[J]. 岩土力学,2002,23(6):778 − 781. [HE Kaisheng. Present construction quality problem of deep mixing cement-soil piles and solving measures[J]. Rock and Soil Mechanics,2002,23(6):778 − 781. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-7598.2002.06.035
[2] 熊营飞, 刘洋. 海水环境下水泥加固不同土质土体的效果研究[J]. 人民长江,2018,49(17):87 − 91. [XIONG Yingfei, LIU Yang. Comparative study on cement reinforcement effect to different soils under seawater environment[J]. Yangtze River,2018,49(17):87 − 91. (in Chinese with English abstract)
[3] 龚晓南. 地基处理手册[M]. 3版. 北京: 中国建筑工业出版社, 2008: 465-470
GONG Xiaonan. Handbook of Foundation Treatment [M]. 3 ed. Beijing: China Architecture & Building Press, 2008. (in Chinese)
[4] 宁宝宽, 陈四利, 刘斌. 环境侵蚀下水泥土力学特性的时间效应分析[J]. 水文地质工程地质,2005,32(2):82 − 86. [NING Baokuan, CHEN Sili, LIU Bin. The timing effects of mechanical properties of cemented soil under environmental erosion[J]. Hydrogeology and Engineering Geology,2005,32(2):82 − 86. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-3665.2005.02.018
[5] 邢皓枫, 张好, 李浩铭. 高含盐水泥土的力学特性及微观结构研究[J]. 水文地质工程地质,2021,48(3):102 − 109. [XING Haofeng, ZHANG Hao, LI Haoming. Mechanical characteristics and microstructure of salt-rich cement-soil[J]. Hydrogeology & Engineering Geology,2021,48(3):102 − 109. (in Chinese with English abstract)
[6] 丁继辉, 冯俊辉, 张攀星, 等. CFG芯水泥土环组合桩复合地基动力特性试验研究[J]. 工程力学,2015,32(增刊 1):284 − 288. [DING Jihui, FENG Junhui, ZHANG Panxing, et al. Experimental study on dynamic characteristics of composite foundations of rammed cement-soil loop piles with CFG cores[J]. Engineering Mechanics,2015,32(Sup 1):284 − 288. (in Chinese with English abstract)
[7] 李普, 樊恒辉, 史祥, 等. 地震荷载下水泥土循环剪切特性研究[J]. 岩石力学与工程学报,2016,35(增刊 2):4227 − 4234. [LI Pu, FAN Henghui, SHI Xiang, et al. Study on cyclic shear characteristics of cement-soil under seismic loading[J]. Chinese Journal of Rock Mechanics and Engineering,2016,35(Sup 2):4227 − 4234. (in Chinese with English abstract)
[8] 商冉. 钢纤维陶粒混凝土抗氯离子侵蚀性能的研究[J]. 水文地质工程地质,2018,45(3):111 − 117. [SHANG Ran. Study on resistance to chloride ion erosion of SFRLC[J]. Hydrogeology & Engineering Geology,2018,45(3):111 − 117. (in Chinese with English abstract)
[9] “纳米制造的基础研究”重大研究计划: “中国制造”开启纳米精度时代[N/OL]. 中国科学报, (2019-02-25)[2021-05-10].
“Fundamental Research of Nanomanufacturing” major research plan: “Made in China” opens the era of nano precision[N/OL]. China Science Daily, 2019-02-25[2021-05-10]. http://www. nsfc. gov. cn/Portals/0/fj/fj20190226__01. pdf. (in Chinese)
[10] 朱孔赞, 李因文, 朱化雨, 等. 纳米改性水泥的研究进展[J]. 新世纪水泥导报,2011,17(3):6 − 10. [ZHU Kongzan, LI Yinwen, ZHU Huayu, et al. Research progress of nano-modified cement[J]. Cement Guide for New Epoch,2011,17(3):6 − 10. (in Chinese) doi: 10.3969/j.issn.1008-0473.2011.03.003
[11] OLTULU M, ŞAHIN R. Single and combined effects of nano-SiO2, nano-Al2O3 and nano-Fe2O3 powders on compressive strength and capillary permeability of cement mortar containing silica fume[J]. Materials Science and Engineering:A,2011,528(22/23):7012 − 7019.
[12] HOSSEINPOURPIA R, VARSHOEE A, SOLTANI M, et al. Production of waste bio-fiber cement-based composites reinforced with nano-SiO2 particles as a substitute for asbestos cement composites[J]. Construction and Building Materials,2012,31:105 − 111. doi: 10.1016/j.conbuildmat.2011.12.102
[13] MOHAMMADI M, HESARAKI S, HAFEZI-ARDAKANI M. Investigation of biocompatible nanosized materials for development of strong calcium phosphate bone cement: comparison of nano-titania, nano-silicon carbide and amorphous nano-silica[J]. Ceramics International,2014,40(6):8377 − 8387. doi: 10.1016/j.ceramint.2014.01.044
[14] GHASABKOLAEI N, JANALIZADEH A, JAHANSHAHI M, et al. Physical and geotechnical properties of cement-treated clayey soil using silica nanoparticles: an experimental study[J]. The European Physical Journal Plus,2016,131(5):134. doi: 10.1140/epjp/i2016-16134-3
[15] 朱向荣, 王立峰, 丁同福. 纳米硅水泥土工程特性的试验研究[J]. 岩土工程技术,2003,17(4):187 − 192. [ZHU Xiangrong, WANG Lifeng, DING Tongfu. Study on engineering properties of nanometer silica and cement-stabilized soil[J]. Geotechnical Engineering Technique,2003,17(4):187 − 192. (in Chinese with English abstract) doi: 10.3969/j.issn.1007-2993.2003.04.001
[16] 王立峰, 翟惠云. 纳米硅水泥土抗压强度的正交试验和多元线性回归分析[J]. 岩土工程学报,2010,32(增刊 1):452 − 457. [WANG Lifeng, ZHAI Huiyun. Orthogonal test and regression analysis of compressive strength of nanometer silicon and cement-stabilized soils[J]. Chinese Journal of Geotechnical Engineering,2010,32(Sup 1):452 − 457. (in Chinese with English abstract)
[17] 王文军. 纳米矿粉水泥土固化机理及损伤特性研究[D]. 杭州: 浙江大学, 2004
WANG Wenjun. Study on reinforcement mechanism and damage performance of cemented soil stabilized with nanometer material[D]. Hangzhou: Zhejiang University, 2004. (in Chinese with English abstract)
[18] BIN-SHAFIQUE S, RAHMAN K, YAYKIRAN M, et al. The long-term performance of two fly ash stabilized fine-grained soil subbases[J]. Resources, Conservation and Recycling,2010,54(10):666 − 672. doi: 10.1016/j.resconrec.2009.11.007
[19] COATES G, 肖立志, PRAMMER M. 核磁共振测井原理与应用[M]. 孟繁萤, 译. 北京: 石油工业出版社, 2007
COATES G, XIAO Lizhi, PRAMMER M. Principle and application of NMR logging [M]. MENG Fanying, trans. Beijing: Petroleum Industry Press, 2007. (in Chinese)
[20] YAO Y B, LIU D M, CHE Y, et al. Petrophysical characterization of coals by low-field nuclear magnetic resonance (NMR)[J]. Fuel,2010,89(7):1371 − 1380. doi: 10.1016/j.fuel.2009.11.005
-
图(9)
表(3)
计量
- 文章访问数: 1330
- PDF下载数: 116
- 施引文献: 0