| 引用本文: | 张轩硕,李宏波,李盛,等.高活性硅灰改性渠道衬砌胶材性能及微观机理研究[J].灌溉排水学报,0,():-. |
| zhangxuanshuo,lihongbo,lisheng,et al.高活性硅灰改性渠道衬砌胶材性能及微观机理研究[J].灌溉排水学报,0,():-. |
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| 摘要: |
| 【目的】宁夏引黄灌区混凝土衬砌受土壤盐渍化影响导致强度衰减、微观结构破坏，为了探明矿物掺合料对衬砌胶材宏微观性能的影响。【方法】分别以普通硅酸盐水泥(P·O)、硫铝酸盐水泥(SAC)、铝酸盐水泥(AC)为基础，以硅灰为替代料，制备了15种复合胶材，通过SEM、EDS、XRD表征手段和抗压强度试验，研究复合胶材力学行为演变规律，揭示其微观水化机理。【结果】掺入6%硅灰显著提高P·O早期强度，C-S-H凝胶和AFt晶体彼此胶结互锁构成三维网络结构，有效减缓了因Ca(OH)2简单堆叠引起剪切滑移而造成基体早期强度衰退，C-S-H凝胶Ca/Si降低、聚合度增加，保证了体系强度稳定；SAC浆体3、28 d龄期强度均随着硅灰替代率的增加先增大后减小，硅灰的成核效应、火山灰效应促使SAC水化产物增多，粗棒状AFt晶体在硬化浆体起骨架功能并被AH3凝胶覆盖，形成更坚强的联合体；随着硅灰替代率的增加，AC浆体3、28 d龄期强度呈负增长，90 d龄期强度先增大后降低，掺入4%硅灰制约了CAH10、C2AH8的转晶反应，孔隙率明显降低，改善了AC后期强度倒缩现象。【结论】适宜硅灰掺量能提高衬砌板胶材强度、优化体系微观形貌，从而提升抗渗特性，建议将硅灰应用至生产渠道衬砌。 |
| 关键词: 硅灰；渠道衬砌胶材；力学性能；C2AH8；微观结构分析 |
| DOI： |
| 分类号:TU528.041 |
| 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)。宁夏自然科学(编号:2021AAC03080) |
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| Study on properties and micromechanism of channel lining cementing material modified with high activity silica fume |
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zhangxuanshuo, lihongbo, lisheng, dingyongfa
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Ningxia University
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| Abstract: |
| Abstract:【Objective】The concrete lining in ningxia yellow river diversion irrigation area is affected by soil salinization, which leads to strength attenuation and microstructure damage.【Method】Based on ordinary Portland cement (P·O), Sulphoaluminate cement (SAC) and Aluminate cement (AC), respectively, and silica fume as a substitute, 15 kinds of composite cementing materials were prepared. Through SEM, EDS, XRD characterization and compressive strength test, the evolution law of mechanical behavior of composite adhesives was studied, and its micro hydration mechanism was revealed.【Result】The addition of 6% silica fume significantly increased the early strength of P·O, and C-S-H gel and AFt crystals cemented and interlocked with each other to form a three-dimensional network structure, effectively slowing down the early strength decline of the matrix due to shear slip caused by simple stacking of Ca(OH)2. The Ca/Si of C-S-H gel decreased and the degree of polymerization increased, ensuring the stability of the system strength; The strength of SAC pastes at 3 and 28 days of age first increases and then decreases with the increase of silica fume replacement rate. The nucleation effect and pozzolanic effect of silica fume promote the increase of SAC hydration products. The coarse rod like AFt crystals play a skeleton role in hardening pastes and are covered by AH3 gel, forming a stronger combination; With the increase of replacement rate of silica fume, the strength of AC paste at the age of 3 and 28 days showed a negative increase, and the strength at the age of 90 days increased first and then decreased. The addition of 4% silica fume restricted the crystallization reaction of CAH10 and C2AH8, and the porosity decreased significantly, which improved the strength reversion phenomenon at the later stage of AC.【Conclusion】The appropriate amount of silica fume can improve the strength of the lining board cementing material, optimize the microscopic morphology of the system, thus improving the impermeability characteristics. It is recommended that silica fume be applied to the production channel lining. |
| Key words: Silica fume; Channel lining cementing material; Mechanical property; C2AH8; Microstructure analysis |
