| 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】针对宁夏地区含盐量为23%超硫酸盐渍土，通过正交试验方法，研究了水泥掺量、粉煤灰掺量、硅灰掺量及脱硫石膏掺量对固化盐渍土无侧限抗压强度的影响；利用XRD、SEM和EDS探究了两种较高强度配和比固化盐渍土的反应产物、微观结构和固化机理。【结果】结果表明：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；四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】将粉煤灰、硅灰、脱硫石膏协同水泥用于渠道盐渍土固化具有可行性，为三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： |
| 分类号:TU411. 7 |
| 基金项目:国家自然科学(52069025)；宁夏高等学校一流学科(水利工程学科)资助项目(NXYLXK2021A03)。 |
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| Study on strength and micro mechanism of industrial waste residue cooperating with cement curing channel foundation saline soil |
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dingyongfa
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.College of Civil and Hydraulic Engineering, Ningxia University
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| Abstract: |
| 【Objective】 The concrete channel slab of the yellow diversion irrigation area of Yinbei Plain in Ningxia is vulnerable to frost swelling, corrosion and dissolution, and experimental research is carried out to solve the problem of saline land base engineering disease of the channel channel. 【Method】 For the salt content of 23% super sulfate soil in Ningxia, the influence of cement mixing, fly ash mixing, silicon ash mixing and desulfurization gypsum mixing on the unrestricted compressive strength of solidified saline soil was studied by orthogonal test method. XRD, SEM and EDS were used to explore the reaction products, microstructure and curing mechanism of solidified saline soil with two high strength ratios.【Result】 The results show that the primary and secondary orders of the compression strength are cement, silica ash, fly ash and desulfurization gypsum. The unconfined compressive strength of cement cured saline soil with fly ash, silica fume and desulfurized gypsum was significantly improved compared with that of uncured saline soil. And the 6% cement cement, 10% fly ash, 6% desulfurization gypsum, and 5% silica cement have the best curing effect. The synergistic interaction between the four curing agents promoted the silica and aluminum oxygen microlattice dissolution in the mixture. In combination with Ca2+ in soil to generate C-S-H, C-A-H gels and AFt, these gels stack with each other to form the overall spatial skeleton structure, increasing the compressive strength of cured saline soil; EDS energy spectrum analyzes the typical morphology generator in SEM micrograph and verifies the generator composition. 【Conclusion】 It is feasible to use fly ash, silicon ash and desulfurization gypsum with cement for channel saline soil solidification, It provides reference for the application of cement cement. |
| Key words: Cure saline soil; compressive strength; microstructure; triaxial test; Curing mechanism |
