At present, microsilica powders in many countries in the world are mostly used for high-strength concrete (HSC), generally above 80 MPa, but if the research and the first application in engineering are described, it should be attributed to the tunnel (Blindtarmen tunnel in Oslo in 1952) [1 ]. In the 1970s and 1980s, with the tunnel engineering powers of North Europe and North America successively promulgating the standards for adding micro-silica fume to concrete, the research and application of micro-silica fume developed rapidly worldwide. Due to the many advantages of the addition of micro silicon powder to radon and sprayed radon, China began to introduce, research and use it in the 1990s, but there are only a few cases for hydraulic and highway use, and no one is used for railway tunnels. Wenjin has not yet formulated uniform relevant standards in China.
The use of micro silicon powder at home and abroad
From the 1980s to the present, 75% of the sprayed plutonium in Europe and the United States is micro-silicon powder sprayed plutonium. The Nordic countries Norway,
Sweden's spray gun is 100% doped with micro silicon powder. A large amount of data shows that micro-silica powder is widely used in high-rise concrete, high-strength concrete (80MPa-130Mpa).
In recent years, domestic successful applications are the Wanjiazhai Yellow River Diversion Project in Shanxi and the underground gas storage cavern at LPG terminal in Shantou, Guangdong. Table 1 shows some typical examples of tunnel construction at home and abroad.
Huayuan Wollastonite, Xinyu Wollastonite, Jiangxi Wollastonite
Physical properties and chemical composition of micro silicon powder
Micro-silica powder is filtered out of the furnace soot and contains a large amount of fine amorphous silicon dioxide (SiO2) particles. It is a by-product of the reduction of high-purity quartz, coke and wood chips in the electric arc furnace during the production of ferrosilicon or metal silicon.