| Cite this article: | 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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| DOI： |
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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 |
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