Densified silica fume in slurry hardened paste has obvious cluster effect, part of microsilica cluster has obvious crack, make neat paste porosity increase, resulting compressive strength of pulp reduction, the need for adequate mixing and scatter; Densified silica fume in concrete system, as first add coarse aggregate, has strong friction effect, after high power mixer scattered, clusters are less able to relatively dispersed, volcano ash reaction of silica fume can improve the interfacial transition zone, the concrete compressive strength increased.
Silica fume in cement concrete can well fill cement particle gap, make the slurry more micro dense, it also combine with the free Ca (OH) to form stable calcium silicate hydrates 2CaO, SiO2, H2O, the hydrate gel strength is higher than Ca (OH) crystal, mainly in:
(1) increase the intensity. The compressive strength and flexural strength of concrete are greatly increased, and the compressive strength can be increased 10-30% and the flexural strength is increased more than 10%, by adding 5-10% micro silica fume.
(2) increase the density. The anti permeability performance was increased by 5 – 18 times, and the anti – chemical ability was raised by more than 4 times.
(3) frost resistance: after 300 to 500 cycles of rapid freezing and thawing, the relative elastic modulus of micro silica powder reduce 10 to 20%, while ordinary concrete is 25 – 50 cycles, and the relative elastic modulus is low to 30 – 73%.
(4) early strength: micro silica fume concrete makes the induction period shorten and has the characteristics of early strength.
(5) anti abrasion and control cavitation: silica fume concrete is 0.5 – 2.5 times higher than that of ordinary concrete, and the ability to resist cavitation is 3 – 16 times.
Densified silica fume present situation:
Because SiO2 of the micro silica fume is amorphous substance, high activity, fine particles, large surface area, has excellent physical and chemical properties, in the past it is considered as a kind of industrial waste, is now increasingly considered a valuable resource, without powder grinding. It can be widely used in some important fields, such as special engineering concrete, refractory, cement, etc.
At present, the demand for silica fume in the international market is increasing year by year. The total output of micro silica fume produced by the main producers of foreign micro silica, such as the United States, Russia, Japan and Norway is more than 640 thousand tons / year, and still can not meet the market demand. Because the production of Chinese ferrosilicon and silicon metal in the world in a prominent position (in 2006 accounted for about 2/3 of the world’s total output), micro silica associated is paied attention by foreign terminal customers, not only investment gradually the monopoly of resources, and the R & D center have moved to Chinese. But because need buy micro silica from most of the domestic ferroalloy manufacturers, such as ferroalloys in the northwest of China, proceed in China and sell to the international market that used in the fields of construction, cement, chemical fertilizer, etc. The profits are very high.
Densified silica fume factory in China:
Due to China large source, there are many silica fume manufacturers in China, famous companies are Sichuan Langtian, Huatuo, Yuanye, Giant, Sanyuan, Winitoor, Henan Superior Abrasives, and other.
In which Henan Superior Abrasives is the very famous microsilica supplier, so our factory can meet customers’ various requirements. If you have any need, please contact us by E-mail sales@superior-abrasives.com or directly contact us on the following form, thank you.
