摘要
采用丙烯酸、聚氧化乙烯醚及硅烷偶联剂合成梳状结构的大分子主链,并接枝纳米SiO_(2)粒子为侧链,制备出纳米SiO_(2)的分散液(CNS)。通过优化参数组合,提出了合成的最佳工艺和配比。采用SEM和动态光散射表征CNS中纳米SiO_(2)形貌和粒径分布。探讨了掺CNS对水泥基材料水化热、凝结时间、孔结构、水化产物、混凝土力学性能和抗渗性能的影响。试验结果表明,掺CNS可明显提高水化放热速率,促进水泥的早期水化并加速水化产物的形成和沉淀,加快水化温升,同时缩短凝结时间。掺CNS对水化产物的影响表现为:在养护7 d时,促进生成C-S-H凝胶,降低了水化产物中氢氧化钙(CH)的含量;养护28 d时,加速了水化产物的形成,增加水化产物中CH的含量。宏观性能表现为混凝土的7、28 d抗压强度和抗渗性能提高。
In this paper,a kind of colloidal of nano-silica(CNS)was prepared,which was a comb-like structure polymer.Its main chain synthesized by acrylic acid,polyoxyethylene ether and silane coupling agent,side chain grafted with nanosilica particles.By optimizing the parameters,a reasonable synthesis process and formula were determined.The morphology and particle size distribution of the nano-silica in CNS were characterized by scanning electron microscope(SEM)and dynamic light scattering(DLS).The effects of different amounts of CNS on cement hydration heat,setting time,pore structure,hydration products,mechanical properties and impermeability of concrete were evaluated.The test results show that the addition of CNS can increase the hydration heat release rate,promote the early hydration of cement,accelerate the formation and precipitation of hydration products,increase the hydration temperature and shorten the setting time.The effect on hydration products is that CNS promotes the formation of C-S-H gel at 7 d and reduces the content of Ca(OH)2(CH)in hydration products.At 28 d,CNS accelerates the formation of hydration products and increases the content of CH in hydration products.The macroscopic performance shows that the 7 and 28 d compressive strength and impermeability of concrete are improved.
作者
梁锐
孔森
张琰
刘佳龙
LIANG Rui;KONG Sen;ZHANG Yan;LIU Jialong(China Electric Power Research Institute,Beijing 100192,China)
出处
《硅酸盐通报》
CAS
北大核心
2023年第4期1183-1193,共11页
Bulletin of the Chinese Ceramic Society
基金
国家电网公司科技项目(5200-20223098A-1-1-ZN)。
关键词
水泥基材料
纳米二氧化硅
二氧化硅分散液
梳状结构
水化产物
cement-based material
nano-silica
colloidal of silica
comb-like structure polymer
hydration product
