ISSN 1008-5548

CN 37-1316/TU

2024年30卷  第5期
<返回第5期

多元固废基胶凝体系固化盐渍土的力学性能

Mechanical properties and mechanism of cement‑based multi‑component solid waste solidified saline soil

王 紫1a,1b ,周志尧1a,1b ,张 喆1a,1b ,兰永军1a,1b ,孟松松2 ,李宏波1

1. 宁夏大学 a. 土木与水利程学院, b. 宁夏土木工程防震减灾工程技术研究中心, c. 宁夏节水灌溉与水资源调控工程技术研究中心,宁夏 银川 750021;2. 谢菲尔德大学 土木与结构工程系,英国 南约克郡 S10 2TN


引用格式:

王紫, 周志尧, 张喆, 等. 多元固废基胶凝体系固化盐渍土的力学性能[J]. 中国粉体技术, 2024, 30(5): 57-69.

WANG Z, ZHOU Z Y, ZHANG Z, et al. Mechanical properties and mechanism of cement‑based multi‑component solid waste solidified saline soil[J]. China Powder Science and Technology, 2024, 30(5): 57−69.

DOI:10.13732/j.issn.1008-5548.2024.05.006

收稿日期: 2024-05-22, 修回日期: 2024-06-15, 上线日期: 2024-07-24。

基金项目: 国家自然科学基金项目,编号:52069025;宁夏自然科学基金重点项目,编号:2023AAC02025; 宁夏高等学校一流学科(水利 工程学科)资助项目,编号:NXYLXK2021A03。

第一作者简介:王紫(1998—),女,硕士生,研究方向为盐渍土固化。E-mail:wangzi596@163.com。

通信作者简介:李宏波(1977—),男,副教授,博士,硕士生导师,研究方向为土木工程新材料。E-mail:lihongbo@126.com。


摘要:【目的】改善宁夏地区工程盐渍土地基的冻胀和腐蚀问题。【方法】采用水泥、 粉煤灰、 硅灰和硅锰渣作为盐渍土 的固化剂,设计四因素三水平正交试验方案,通过无侧限抗压强度试验和三轴试验,探讨不同固化剂掺量(质量分数,下 同)对盐渍土抗压强度和抗剪强度的影响;采用扫描电子显微镜(scanning electronic microscopy,SEM))和X射线衍射 (X‑ray diffraction,XRD)表征分析固化盐渍土的强度提升机制。【结果】水泥和硅灰提升固化盐渍土的早期强度作用较为 显著,随掺量的增加,粉煤灰强度呈先增后减的趋势,硅锰渣结构较为稳定,需要充足的碱性环境来激发胶凝能力;水泥、 粉煤灰、 硅灰和硅锰渣4种因素对固化盐渍土抗压强度的影响程度由高到低的顺序为水泥、硅灰、粉煤灰、硅锰渣;水泥、 粉煤灰、 硅灰和硅锰渣掺量分别为3%、 5%、 5%和3%时固化效果最佳,为最佳配合比;固化盐渍土生成棒状的钙矾石 (aluminate ferro-copper-calcium sulfate,AFt)和网状的水化铝酸钙(calcium aluminate hydrate,C-A-H)等水化产物相互联 结,微观结构变得致密。协同作用提升了固化盐渍土的强度。【结论】采用水泥、 粉煤灰、 硅灰和硅锰渣最佳配合比能够 使盐渍土地基固化,改善地基的冻胀和腐蚀问题。

关键词: 固化盐渍土; 无侧限抗压强度试验; 三轴试验; 微观分析

Abstract

Objective To address the frost heave and corrosion issues in engineering saline soil foundation in Ningxia, and to improve the comprehensive utilization of solid waste in the Ningxia Hui Autonomous Region, this study focuses on the analysis of the interac tion of a composite curing agent used to solidify saline soil.

Methods Every year, industrial areas in Ningxia Hui Autonomous Region produce a significant amount of solid waste, including fly ash, silica fume, and silicon manganese slag. This waste exhibits good pozzolanic activity and can be effectively cured using alkali-activated materials. To this end, this paper employs cement, fly ash, silica fume, and silicomanganese slag as curing agents for saline soil. To comprehensively study the influence of mixed cement, fly ash, silica fume, and silicon manganese slag on the strength characteristics of solidified saline soil, we used an orthogonal test to design a four-factor three-level orthogonal test scheme. This method selects a representative experimental scheme from many experimental conditions, effectively solving the problem of many factors and a large number of tests. The experiment is discussed from two perspectives: macro mechanics and micro mechanism. The mechanical properties of solidified saline soil are verified using the unconfined compressive strength test and triaxial test. The influence of different curing agent content on the compressive strength and shear strength of saline soil is discussed. The strength improvement mechanism inside the solidified saline soil is characterized and analyzed using scanning electronic microscopy (SEM) and X-ray diffraction (XRD). The microstructure of cementitious materials, including particle size, shape, distribution, and surface characteristics, can be observed using the high-resolution ability of SEM. XRD is a pow erful tool for identifying various crystal phases in cementitious materials and analyzing their crystal structure and phase composi tion. The microstructure, composition, and crystal structure information of the material can be analyzed more effectively by com bining SEM and XRD. This allows for a better determination of the main components of the cementitious material and the reac tion mechanism between the curing agents.

Results and Discussion Compared to the 7-day age, the compressive and shear strength of the solidified saline soil significantly improved after 28 days. The compressive strength of the solidified saline soil is influenced by cement, silica fume, fly ash, and silicon manganese slag in that order of importance. The optimal mix ratio for cement, fly ash, silica fume, and silicon manga nese slag is achieved when their respective contents are 3%, 5%, 5%, and 3%. This ratio results in the best curing effect. The hydration reaction time of cement is brief, creating an alkaline environment for silica fume, fly ash, and silicon manganese slag. This reaction produces cementitious materials that effectively enhance the strength of solidified saline soil. Silica fume contains a significant amount of SiO2,which reacts with Ca(OH)2 produced by cement hydration to form cementitious materials such as C-S-H, thereby improving strength. Cement and silica fume have a significant effect on improving the early strength of solidified saline soil. The strength of fly ash increases initially with an increase in dosage, but then decreases due to the 'ball effect'. The structure of silicon-manganese slag is relatively stable, but it requires a sufficient alkaline environment to stimulate its cementi tious ability. The cementing material produced by the curing agent improves the mechanical properties of solidified saline soil in two ways: firstly, by enhancing the bonding effect between soil particles through its own cementation, and secondly, by filling the pores and cracks of the saline soil, thereby improving the integrity of the soil structure. The solidified saline soil produces hydration products, such as rod-shaped ettringite (AFt) and reticular calcium silicate hydrate (C-A-H), which are interlinked. This results in a denser microstructure and improved strength of the solidified saline soil due to the synergistic effect. Compared to the 7-day age, the reactions between the curing agents at 28 days, such as hydration, ion exchange, and pozzolanic reac tions, are more sufficient, leading to the formation of more cementitious substances. As a result, the compressive and shear strength of the solidified soil are higher at 28 days.

Conclusion To solidify saline soil foundation in the channel, it is recommended to use a mix ratio of 3% cement, 5% fly ash, 5% silica fume, and 3% silicon manganese slag. These ratios were determined based on research results and provide a theoreti cal reference for the synergistic solidification of cement and multiple solid wastes in channel saline soil foundation.

Keywords:solidified saline soil; unconfined compressive strength test; triaxial test; microscopic analysis


参考文献(References)

[1]徐鹏程, 冷翔鹏, 刘更森, 等. 盐碱土改良利用研究进展[J]. 江苏农业科学, 2014, 42(5): 293-298.

XU P C, LENG X P, LIU G S, et al. Research progress on improvement and utilization of saline-alkali soil[J]. Jiangsu Agricultural Sciences, 2014, 42(5): 293-298.

[2]李芳, 李斌, 陈建. 中国公路盐渍土的分区方案[J]. 长安大学学报(自然科学版), 2006, 26(6): 12-14, 89.

LI F, LI B, CHEN J. Highway-related dividing scheme of salty soil[J]. Journal of Chang,an University (Natural Science Edition), 2006, 26(6): 12-14, 89.

[3]陈康亮, 刘长武, 杨伟峰, 等. 基于生石灰和粉煤灰改良硫酸盐渍土的强度特性[J]. 科学技术与工程, 2020, 20(26):10888-10893.

CHEN K L, LIU C W, YANG W F, et al. Strength characteristics of sulphate saline soil modified by lime and fly ash[J].Science Technology and Engineering, 2020, 20(26): 10888-10893.

[4]周纯秀, 崔洪海, 张中丽, 等.改良碳酸盐渍土路基填料的力学性质[J]. 哈尔滨工业大学学报, 2022, 54(9): 93-100.

ZHOU C X, CUI H H, ZHANG Z L, et al. Mechanical properties of improved carbonate soil roadbed filler[J]. Journal of Harbin Institute of Technology, 2022, 54(9): 93-100.

[5]李宏波, 田军仓, 边兴. 掺加硅灰和石灰条件下的超盐渍土抗剪特征研究[J]. 广西大学学报(自然科学版), 2016,41(4): 1145-1152.

LI H B, TIAN J C, BIAN X. Investigation on shear characteristics of hypersaline soil improved by lime and silica fume[J].Journal of Guangxi University (Natural Science Edition), 2016, 41(4): 1145-1152.

[6]胡其志, 霍伟严, 马强, 等. MICP联合纤维加筋黄土的力学性能及水稳性研究[J]. 人民长江, 2023, 54(8): 227-232, 248.

HU Q Z, HUO W Y, MA Q, et al. Research on mechanics and water stability of fiber reinforced loess combined with MICP[J].Yangtze River, 2023, 54(8): 227-232, 248.

[7]郭东悦, 邱明喜, 杨庆港, 等. 微生物-活性氧化镁固化盐渍土强度变化规律研究[J]. 工程勘察, 2023, 51(8): 11-17, 66.

GUO D Y, QIU M X, YANG Q G, et al. Study on strength characteristics of microbial-reactive magnesia oxide solidified saline soil[J]. Geotechnical Investigation & Surveying, 2023, 51(8): 11-17, 66.

[8]王亮, 慈军, 杨志豪, 等. 电石渣-火山灰质胶凝材料固化盐渍土试验研究[J]. 新型建筑材料, 2020, 47(5): 46-49, 67.

WANG L, CI J, YANG Z H, et al. Experimental study on solidified saline soil with calcium carbide slag and volcanic ash cementitious materials[J]. New Building Materials, 2020, 47(5): 46-49, 67.

[9]丁永发, 李宏波, 张轩硕, 等. 工业废渣协同水泥固化渠道地基盐渍土强度及微观机理研究[J]. 灌溉排水学报, 2022,41(6): 113-120.

DING Y F, LI H B, ZHANG X S, et al. Using mixture of industrial waste residues and cement to reinforce channel foundation in salinized soils[J]. Journal of Irrigation and Drainage, 2022, 41(6): 113-120.

[10]谢宇轩, 朱连勇, 王立成. 工业及建筑废弃物固化盐渍土的力学性能和路用性能影响[J]. 科学技术与工程, 2023,23(19): 8393-8401.

XIE Y X, ZHU L Y, WANG L C. Experimental study on the influence of road performance of saline soil solidified by industrial and construction waste materials[J]. Science Technology and Engineering, 2023, 23(19): 8393-8401.

[11]宫经伟, 林浩然, 王亮, 等. 基于正交试验的全固废复合胶凝材料固化盐渍土的力学性能[J]. 科学技术与工程, 2021, 21(7): 2865-2872.

GONG J W, LIN H R, WANG L, et al. Mechanical propertiesof solidified saline soil of all solid waste composite cementitious material based on orthogonal test[J]. Science Technology and Engineering, 2021, 21(7): 2865-2872.

[12]张卫兵, 雷过, 周瑞璞, 等. 冻融作用下固化盐渍土的强度劣化及微观机理研究[J]. 科学技术与工程, 2022, 22(20):8869-8876.

ZHANG W B, LEI G, ZHOU R P, et al. Strength deterioration of consolidated saline soils under freeze-thaw action and micromechanics[J]. Science Technology and Engineering, 2022, 22(20): 8869-8876.

[13]李舒洁, 常立君. 再生微粉固化黄土状盐渍土的力学特性和微观机理[J]. 中国粉体技术, 2022, 28(5): 30-39.

LI S J, CHANG L J. Mechanical properties and microscopic mechanism of loess-like saline soil solidified by regenerated micronized powder[J]. China Powder Science and Technology, 2022, 28(5): 30-39.

[14]单龙, 李宏波, 程银银, 等.水泥-镁渣固化盐渍土力学性能实验[J]. 中国粉体技术, 2023, 29(5): 8-16.

SHAN L, LI H B, CHENG Y Y, et al. Mechanical properties test of solidified saline soil with cement-magnesium slag[J].

China Powder Science and Technology, 2023, 29(5): 8-16.

[15]唐少容, 杜鹏, 李昊天, 等. 由石蜡基相变材料和煤渣改良的粉砂土的冻融性能[J]. 中国粉体技术, 2024, 30(1):123-131.

TANG S R, DU P, LI H T, et al. Freeze-thaw properties of silty sand modified by paraffin-based phase change materials and cinder[J]. China Powder Science and Technology, 2024, 30(1): 123-131.

[16]聂轶苗, 刘淑贤, 牛福生, 等. 粉煤灰研究进展及展望[J]. 混凝土, 2010(4): 62-65.

NIE Y M, LIU S X, NIU F S, et al. Research progress and developing prospect of fly ash[J]. Concrete, 2010(4): 62-65.

[17]李宏波, 田军仓, 南红兵, 等. 几种固化剂对渠道盐渍土地基力学性能影响的试验研究[J].灌溉排水学报, 2018, 37(12): 94-99.

LI H B, TIAN J C, NAN H B, et al. Efficacy of four consolidation agents in improving mechanical properties of salinized foundation soil of channels[J]. Journal of Irrigation and Drainage, 2018, 37(12): 94-99.

[18]黄太忠. 硅锰渣在建筑材料中的利用研究[D]. 重庆: 重庆大学, 2012.

HUANG T Z. Study on the utilization of SiMn slag in construction m aterials[D]. Chongqing: Chongqing University, 2012.

[19]杨晓松, 刘井强, 党进谦. 粉煤灰改良氯盐渍土工程特性试验研究[J]. 长江科学院院报, 2012, 29(11): 82-86.

YANG X S, LIU J Q, DANG J Q. Experimental research on the engineering property of chlorine saline soil improved by fly ash[J]. Journal of Yangtze River Scientific Research Institute, 2012, 29(11): 82-86.

[20]中华人民共和国住房和城乡建设部. 土工试验方法标准: GB/T 50123—2019[S]. 北京: 中国计划出版社, 2019.

Ministry of Housing and Urban-Rural Development of the People’s Republic of China. Standard for geotechnical testing method: GB/T 50123—2019[S]. Beijing: China Planning Press, 2019.

[21]王泽平. 硅灰对水泥加固土工程性质影响的试验研究[D]. 长春: 吉林大学, 2020.

WANG Z P. Experimental study on the influence of silica fume on the engineering properties of cement reinforced soil[D].Changchun: Jilin University, 2020.

[22]张虎彪. 水泥粉煤灰稳定砖-砼再生碎石的路用性能研究[D]. 银川: 宁夏大学, 2022.

ZHANG H B. Study on the performance of cement fly ash stabilized brick-concrete recycled gravel road[D]. Yinchuan:Ningxia University, 2022.

[23]丑亚玲, 杨双双. 盐渍土工程性质的改良研究进展[J]. 材料导报, 2023, 37(增刊1): 244-250.

CHOU Y L, YANG S S. Research progress on the improvement of saline soil engineering properties[J]. Materials Reports,2023, 37(S1): 244-250.

[24]杨西锋, 尤哲敏, 牛富俊, 等. 固化剂对盐渍土物理力学性质的固化效果研究进展[J]. 冰川冻土, 2014, 36(2): 376-385.

YANG X F, YOU Z M, NIU F J, et al. Research progress in stabilizers and their effects in improving physical and mechanical properties of saline soil[J]. Journal of Glaciology and Geocryology, 2014, 36(2): 376-385.

[25]王沛, 王晓燕, 柴寿喜. 滨海盐渍土的固化方法及固化土的偏应力-应变[J]. 岩土力学, 2010, 31(12): 3939-3944.

WANG P, WANG X Y, CHAI S X. Solidifying methods for inshore saline soil and its deviator stress-strain[J]. Rock and Soil Mechanics, 2010, 31(12): 3939-3944.

[26]李宏波, 田军仓, 陈文兵, 等. 水泥硅灰固化超盐渍土的抗剪强度试验[J]. 桂林理工大学学报, 2015, 35(3):508-513.

LI H B, TIAN J C, CHEN W B, et al. Shear strength of solidified hypersaline soil with cement and silica fume[J]. Journal of Guilin University of Technology, 2015, 35(3): 508-513.

[27]张洁雅, 杨帆, 曹家玮, 等. 三元工业废渣协同水泥固化土的基本特性和机理分析[J/OL]. 长江科学院院报, 2023: 1-8. (2023-10-25). https://kns.cnki.net/kcms/detail/42.1171.TV.20231024.1721.010.html.

ZHANG J Y, YANG F, CAO J W, et al. Basic characteristics and mechanism analysis of ternary industrial waste cooperated cement solidified soil[J/OL]. Journal of Yangtze River Scientific Research Institute, 2023: 1-8. (2023-10-25).

https://kns.cnki.net/kcms/detail/42.1171.TV.20231024.1721.010.html.

[28]LIU Y W, WANG Q, LIU S W, et al. Experimental investigation of the geotechnical properties and microstructure of lime-stabilized saline soils under freeze-thaw cycling[J]. Cold Regions Science and Technology, 2019, 161: 32-42.