Semi-encrypted silica fume for office building concrete

Semi-encrypted silica fume for office building concrete: This semi-encrypted Microsilica is often added to concrete used in the construction of office buildings to increase the corrosion resistance and other properties of the concrete.

The surface of silica particles is hydrophilic and has a large surface area. The amount of water required to wet such a large surface area is relatively large. Therefore, as the Silica Fume content increases (greater than 5%), the water requirement or water-cement ratio of the concrete increases when the concrete mix reaches the same slump. Similarly, when the water consumption or the water-cement ratio is kept constant, the concrete becomes more and more sticky as the silica fume content increases. In order to really improve the strength and impermeability of concrete and obtain good compatibility without increasing the water-cement ratio, silica fume is usually used together with water reducing agent or high efficient water reducing agent. The new silica fume concrete has a strong bond and is not easy to separate.

In the range of low micro silicon powder content, i.e. within 5% of cementitious material, silica fume can actually reduce the viscosity of concrete mix, and then the particle shape of silica fume (spherical particles) plays a dominant role, i.e. the "ball lubrication" effect of spherical particles exceeds the "wetting water requirement" effect of high specific surface area. The "ball lubrication" effect dominates over the "wetting water requirement" effect of high specific surface area. In other words, the low dosage of silica fume can not only improve the adhesion of the concrete mix, but also improve the fluidity of the concrete mix and reduce the pumping pressure, which is very suitable for the preparation of high-compaction or self-compacting concrete.