The spread of the novel coronavirus is taking a direct hit on the operations of airlines in Asia. About 500,000 flights taking off and landing in mainland China have been canceled since January, according to aviation information company Cerium. Tourists and business trips have plummeted. On the booking website, there are a large number of air tickets for local routes with a price reduction of nearly 90% compared with the original price and only tens of yuan for a one-way trip.
In February, China's aviation industry recorded its largest single-month loss of 24.59 billion yuan, of which airlines lost 20.96 billion yuan.
Data from the Civil Aviation Administration of China showed that in February, the number of passengers traveling by air fell 84.5% year-on-year to 8.34 million.
The stagnation of the Asian aviation industry has brought volatility to silica fume.
What is micro silica fume for concrete?
Micro silica fume is also well used in the concrete industry. Its physical characteristics include small particles, high purity, and pozzolanic solid activity. Adding micro silica fume to concrete can not only improve the properties of concrete in many aspects but also enhance. The adhesion and cohesion of concrete itself, can make the concrete play its role more and reduce the amount of rebound. The use of micro-silica fume has brought many advantages to the project; not only can the thickness of the concrete be formed at one time, but it also brings a lot of cost savings to the whole project and shorten the time required for the project.
Application of high-performance concrete proportioning design scheme
1) Compatibility: Micro silica fume has good compatibility with water-reducing agents, fly ash, mineral powder, and fiber;
2) Slump: Concrete has strong viscosity due to the phenomenon of gap filling, so the slump design scheme of concrete mixed with silica fume is 2~3cm higher than that of ordinary concrete;
3) The amount of mixing, production, and processing of high-strength concrete and shotcrete, the mixing amount of silica fume is 6~12% of the cement; the mixing amount of concrete for underwater engineering projects is slightly higher; the silica fume is used as a pump When the agent is used, the mixing amount is reduced to about 2%. Finally, the mixing ratio is confirmed by the mixing ratio test. The mixing of micro-silica fume mixed with cement and aggregate shall be constructed in strict accordance with the specifications, and at the same time, the maintenance shall be enhanced.
Ingredients and mixing
Generally speaking, the concrete industry usually uses densified silica fume, so manual or automatic feeding can be used.
2) Because of its unique ultra-fineness, the micro-silica fume must be put in immediately after feeding, and the micro-silica powder cannot be added to the concrete.
3) When the concrete is mixed with silica fume, the mixing time is 30~40s longer than ordinary concrete to obtain good uniformity.
4) There are no special requirements for the concrete of micro silica fume during transportation, just like ordinary concrete.
Watering and maintenance;
1) Vibration of micro-silica fume concrete requires high density, no vibration leakage, and no over-vibration. The vibration time is generally 10~30s;
2) Continuous supply of concrete is required to prevent cold stubble and cause hidden dangers. The stubble time cannot exceed 100 minutes;
3) It is essential to prevent the premature evaporation of water when protecting the concrete from silica fume. Therefore, after pouring, immediately cover the film, and lay sacks for watering and curing.
Use a woven bag for micro-silica fume in a plastic inner sealed bag, and pay attention to waterproof and moisture-proof during storage and transportation.
TRUNNANO is a concrete additives supplier with over 12 years experience in nano-building energy conservation and nanotechnology development. We accept payment via Credit Card, T/T, West Union and Paypal. Trunnano will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.
If you are looking for high quality silica fume, please feel free to contact us and send an inquiry.
The silica fume industry has experienced demand expectations driven by the rise and the off-season tired stock driven by the seasonal decline in two rounds of the market. Affected by the COVID-19 epidemic and other factors, inventories of manufacturers continue to accumulate, putting pressure on market sentiment. In addition to off-season factors, the weak trend of silica fume also reflects the market's concern about the epidemic and some other related enterprises' financial situation.
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