| 引用本文: | 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 Yongfa,LI Hongbo,ZHANG Xuanshuo,et al.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. |
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| 摘要: |
| 【目的】宁夏银北平原引黄灌溉区混凝土渠道板易受盐渍土地基冻胀、腐蚀及溶陷发生破坏，为解决渠道盐渍土地基工程病害问题开展固化盐渍土试验研究。【方法】针对宁夏地区全盐量为23%超硫酸盐渍土，通过正交试验方法，研究了不同水泥掺量（2%、4%、6%）、粉煤灰掺量（10%、20%、30%）、硅灰掺量（1%、3%、5%）及脱硫石膏掺量（3%、6%、9%）对固化盐渍土无侧限抗压强度的影响；利用XRD、SEM和EDS探究了较高强度配合比固化盐渍土的反应产物、微观结构和固化机理。【结果】各因素对抗压强度影响的主次顺序为水泥>硅灰>粉煤灰>脱硫石膏；粉煤灰、硅灰、脱硫石膏协同水泥固化盐渍土无侧限抗压强度较未固化盐渍土有大幅提升，且6%掺量水泥+10%掺量粉煤灰+6%掺量脱硫石膏+5%掺量硅灰固化效果最佳；4种固化剂间的交互协同作用促进了混合物中的硅氧、铝氧微晶格溶解，与盐渍土中Ca2+结合生成C-S-H、C-A-H凝胶以及AFt等物质，这些胶凝体相互堆叠构成整体空间骨架结构，增加了固化盐渍土的抗压强度；EDS能谱检测分析SEM微观图中典型形貌生成物，验证了其生成物成分。【结论】将10%粉煤灰、5%硅灰、6%脱硫石膏协同6%水泥用于渠道盐渍土固化具有可行性，为3种工业废渣协同水泥固化盐渍土工程应用提供参考。 |
| 关键词: 固化盐渍土；抗压强度；微观结构；固化机理 |
| DOI：10.13522/j.cnki.ggps.2022053 |
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| Using Mixture of Industrial Waste Residues and Cement to Reinforce Channel Foundation in Salinized Soils |
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DING Yongfa, LI Hongbo, ZHANG Xuanshuo, LI Sheng
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1. College of Civil and Hydraulic Engineering, Ningxia University, Yinchuan 750021, China;
2. Ningxia Research Center of Technology on Water-saving Irrigation and Water Resources Regulation,
Yinchuan 750021, China; 3. Engineering Research Center for Efficient Utilization of
Water Resources in Modern Agriculture in Arid Regions, Yinchuan 750021, China
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| Abstract: |
| 【Objective】Concrete channel slabs used in the Yellow River diversion irrigation channels in Yinbei Plain in Ningxia province are susceptible to frost swelling, corrosion and dissolution induced by soil salinity. Different mitigation techniques have been proposed and the purpose of this paper is to investigate the efficacy of reinforcing the channel foundation by mixture of cement and industrial residuals. 【Method】The salinized soil in the foundation was reinforced by cement mixed with various industrial residuals at different ratios. Overall, there were three cement ratios (weight/weight): 2%, 4% and 6%, each being mixed with fly ash at ratio of 10%, 20% or 30%; silica fume at ratio of 1%, 3% or 5%, and desulfurization gypsum at ratio of 3%, 6% or 9%. For each reinforced specimen, we measured its strength using unconfined compressive test, and then analyzed its XRD, SEM and EDS images. 【Result】The agents that affected the strength of the reinforced specimens most is ranked in the order of cement>silica ash>fly ash>desulfurization gypsum. The unconfined compressive strength of the reinforced soil was significantly higher than that of untreated soil specimens. Mixing 6% cement with 10% of fly ash, 6% of desulfurization gypsum and 5% of silica fume was optimal. Synergistic interaction between them promoted dissolution of silica and aluminum oxygen micro-lattice. In combination with Ca2+ in the soil, they generated C-S-H, C-A-H gels. These gels stacked with each other forming a spatial skeleton structure, increasing compressive strength of the specimen as a result. EDS energy spectrum analysis of morphology of the SEM images proved the composition of the mixture. 【Conclusion】Reinforcing the salinized soil in channel foundation by mixing it with 10% of fly ash, 5% of silica fume, 6% of desulfurized gypsum and 6% of cement was optimal to solidify the soil. |
| Key words: soil reinforcement; compressive strength; microstructure; salinized; channel foundation |
