シリカフュームをセメントペースト硬化体の微細構造改善にさらに有効活用するために, many researchers at home and abroad have conducted more detailed studies on the optimal conditions for the application of silica fume in cement paste and concrete, including the water-cement ratio, the amount of silica fume, the selection of admixtures and other volcanic ash admixtures and their dosage.
Silica fume in cement paste and concrete applications there is an optimal water-cement ratio range, generally beyond the range, 硬化したセメントペーストのシリカフュームとコンクリートの微細構造の改善が減少します.
As a researcher pointed out, 歳の時に 3 または 7 d in cement mortar, the water-cement ratio is less than 0.45 (水セメント比 0.35, 0.40) of the mortar specimens containing silica fume strength decreases, while the water-cement ratio is equal to 0.45 また 0.50 of the mortar specimens containing silica fume strength increases;
but at the age of 28 または 90 d in cement mortar, the water-cement ratio is less than 0.35, 0.40, 0.50 The strength of mortar specimens containing silica fume is approximately the same;
while the strength of mortar specimens containing silica fume (シリカフュームの含有量に関係なく) 水セメント比が 0.45 より低い;
水セメント比が等しいとき 0.50 and the silica fume admixture is greater than 27.5%, silica fume has a significant effect on the later strength development of the mortar.
Although silica fume (マイクロシリカ) can effectively improve the microstructure of hardened cement paste and concrete, but because of the small particle size and large specific surface area of silica fume, シリカフュームを混ぜたセメントペーストとコンクリート, with the increase of シリカフューム混和剤, 水の需要が増える, and the self-shrinkage also increases. したがって, the amount of silica fume is generally limited to between 5% と 10%, and high efficiency water reducing agent to adjust the water demand, 同時に, there is a compatibility problem between cement, シリカフューム, 混和剤, したがって, when using silica fume must pay attention to its application conditions.
Since the addition of silica fume in concrete may lead to self-shrinkage of concrete, and the addition of silica fume concrete is generally a special requirement of concrete, したがって, the use of silica fume in concrete to harden the cement paste and concrete properties of the beneficial effect at the same time, must minimize the adverse effects brought about by silica fume, the most effective way to solve this problem is the addition of silica fume at the same time mixed with other volcanic ash materials or Other substances, so that they complement each other’s strengths and weaknesses to achieve better technical and economic results. 現在のところ, more research is the use of ultrafine slag and silica fume compounding, またはの使用 フライアッシュとシリカフューム 調合.
Another area of silica fume application conditions are more research is the use of silane on the surface of silica fume pretreatment after mixing into the cement paste or concrete or directly silane and silica fume at the same time into the cement paste or concrete, 彼らは新鮮なセメント ペーストとコンクリートの作業性を向上させることができます。, したがって、硬化したセメントペーストとコンクリートの微細構造を改善します.
