钙对碱激发胶凝材料的促凝增强作用

发布时间：2018-06-27 08:32

  本文选题：钙 + 碱激发胶凝材料　； 参考：《硅酸盐学报》2017年08期

【摘要】：对比研究了不同含钙物质对碱激发胶凝材料凝结时间及强度的影响,并探讨了其影响机制。结果表明:除碳酸钙外,含钙物质具有强烈的促凝作用,由强到弱依次为氯化钙、氢氧化钙、氧化钙;适当掺量的上述含钙物质均具有增强作用,但过量的含钙物质因试样快凝导致强度反而下降。上述含钙物质具有不同促凝增强机制。易溶的氯化钙具有提供非均匀成核基体及生成低钙硅比水化硅酸钙凝胶的共同作用机制,导致少量氯化钙(1.0%)就可使试样凝结时间缩短至10 min以内,但其增强作用只体现于早期。微溶的氢氧化钙只存在"生成凝胶"这单一作用机制,其促凝增强效果变弱。氧化钙与溶液作用生成氢氧化钙,作为非均匀成核基体而促进硅铝聚合反应,但其与溶液作用历时较长,掺量高达5%时才使试样快凝。难溶的碳酸钙溶解度极低,不具备形成非均匀成核基体和生成凝胶的促凝增强机制。
[Abstract]:The effects of different calcium on the setting time and strength of alkaline activated cementitious materials were studied and the mechanism was discussed. The results showed that, except calcium carbonate, calcium containing material had strong effect of promoting coagulation, from strong to weak is calcium chloride, calcium hydroxide, calcium oxide, and the appropriate amount of these calcium compounds can enhance the effect of calcium chloride, calcium hydroxide, calcium oxide, calcium chloride, calcium hydroxide, calcium oxide, calcium carbonate, calcium carbonate and calcium carbonate. However, the strength of excess calcium-containing material decreased due to the rapid solidification of the sample. These calcium-containing substances have different mechanisms of enhancing coagulation. Soluble calcium chloride has the mechanism of providing heterogeneous nucleation matrix and forming calcium silicate gel with low calcium to silicon ratio. A small amount of calcium chloride (1.0%) can shorten the setting time of the sample to less than 10 min, but its strengthening effect is only reflected in the early stage. There is only a single mechanism of "gel formation" in the microsoluble calcium hydroxide, which weakens the enhancement effect of coagulation. Calcium hydroxide is formed by the interaction of calcium oxide with the solution, which acts as a heterogeneous nucleation matrix to promote the polymerization of silicon and aluminum. However, the reaction time between calcium oxide and the solution is longer, and when the content of calcium oxide is as high as 5%, the sample is rapidly solidified. The insoluble calcium carbonate has very low solubility and does not have the mechanism of accelerating coagulation and strengthening the formation of heterogeneous nucleation matrix and gel.
【作者单位】： 中国建筑材料科学研究总院绿色建筑材料国家重点实验室;
【基金】：国家自然科学基金项目(51572252) 国家“863”计划课题(2015AA034701)资助
【分类号】：TQ177
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本文编号：2073321