Sertleşmiş çimento hamurunun mikro yapısının iyileştirilmesinde silis dumanından daha etkin faydalanmak amacıyla, 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, sertleştirilmiş çimento hamuru ve beton mikroyapı iyileştirmesi üzerindeki silis dumanı azaltılacaktır.
As a researcher pointed out, yaşında 3 d veya 7 d in cement mortar, the water-cement ratio is less than 0.45 (su-çimento oranı 0.35, 0.40) of the mortar specimens containing silica fume strength decreases, while the water-cement ratio is equal to 0.45 veya 0.50 of the mortar specimens containing silica fume strength increases;
but at the age of 28 d veya 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 (silis dumanı içeriğinden bağımsız olarak) eşit bir su-çimento oranı ile 0.45 daha düşük;
su-çimento oranı eşit olduğunda 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 (mikrosilika) 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, Böylece çimento hamuru ve beton silis dumanı ile karışır., with the increase of silis dumanı karışımı, su talebi artar, and the self-shrinkage also increases. Öyleyse, the amount of silica fume is generally limited to between 5% ve 10%, and high efficiency water reducing agent to adjust the water demand, aynı zamanda, there is a compatibility problem between cement, silika dumanı, admixtures, öyleyse, 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, öyleyse, 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. Şu anda, more research is the use of ultrafine slag and silica fume compounding, veya kullanımı uçucu kül ve silis dumanı bileşim.
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, taze çimento hamurunun ve betonun işlenebilirliğini artırabilirler, böylece sertleşmiş çimento hamurunun ve betonun mikro yapısını iyileştirir.
