Advantages of Silica Fume in Concrete

What is Silica Fume Powder?

Silica Fume is also called microsilica fume. It is formed by producing a large amount of highly volatile SiO2 and Si gases in a submerged thermal electric furnace. After the gas is discharged, it quickly oxidizes, condenses, and precipitates with the air. It is a by-product of large-scale industrial smelting. The whole process needs to be recycled with dust removal and environmental protection equipment. Because of its low density, it also needs to be encrypted with encryption equipment.

The average particle size of micro silica powder is 0.2um, and the specific surface area is 15000-25000 m2/kg. Its main component is silicon dioxide, with a content of 85% to 95%. The impurity components are metal oxides such as sodium oxide, calcium oxide, iron oxide, and aluminum oxide, and a small amount of elemental carbon, silicon, etc. Because the silica in micro silica powder is an amorphous substance with high activity, small particles, large specific surface area, and excellent physical and chemical properties, it is widely used in concrete, refractory materials, wall materials, cement products, etc. used in special projects. Mortar, flooring, chemical industry, and other important fields.


Silica Fume Powder Can be Divided into:

• Densified silica fume

• Semi-densified silica fume 

• Undensified silica fume

When the natural characteristics of concrete need to be modified or enhanced, silica fume can be added to the solution during batching to increase the strength and durability of the material.

Microsilica Fume used in Concrete Production

The concrete industry is the field with the earliest research, the most achievements, and the widest application in the comprehensive utilization of micro silica fume abroad. Because micro-silica fume has physical and chemical characteristics such as small particles, large specific surface area, high SiO2 purity, and strong volcanic ash activity, adding micro-silica fume as an admixture to concrete can improve various properties of concrete, such as significantly improving the adhesion of plastic concrete. It has excellent properties and cohesiveness, greatly reduces the amount of spring back, increases the thickness of shotcrete at one time, shortens the construction period, saves project costs, etc. In the fields of ordinary high-performance concrete and ultra-high-performance reactive powder concrete, micro-silica fume is used as an admixture to prepare high-strength concrete, and its strength level can reach hundreds of MPa or more. Such as RPC concrete, HPC concrete, pipe pile concrete, etc.

Important Advantages of Micro-silica Powder

Due to its properties, silica fume is widely used around the world where it is needed to improve the strength and durability of concrete.
Here are some of the important advantages of silica fume that make it widely used in the construction and concrete industries:


1. Very stable chemical and physical properties

Microsilica powder is used as a neutral filler and has extremely stable properties, chemically and physically. It does not contain crystal water, does not participate in the curing reaction, and does not affect the reaction process in any way.

2. Improve thermal conductivity

Silica powder can not only improve thermal conductivity, but it can also improve flame retardancy and change bonding speed.

3. Good adsorption performance

Microsilica powder has good adsorption properties and good infiltration of various resins. In addition, it is easy to mix and has no agglomeration.

4. Reduce precipitation and stratification

Due to its reasonable distribution and fine particle size, micro silica powder can effectively eliminate stratification and reduce precipitation.

5. Increase intensity

The reasonable particle size distribution of micro silica fume ensures good hardness, strong densification, and excellent wear resistance. Adding micro-silica fume to concrete can improve the wear resistance, compressive strength, and tensile strength of the cured product. In addition, the resistance to Grindability can be improved by 0.5-2.5 times.

6. Improve insulation

Microsilica powder is pure silicon powder with low impurity content. As such, it has stable chemical and physical properties ensuring that the cured material has good arc resistance and insulation.

7. Reduce total costs

The bulk density of micro silica powder is between 0.2 and 0.8 or 1.0 and 2.2. When used as a polymer filler material, micro-silica powder can reduce the total cost of the product by saving the amount of polymer and minimizing the load.

8. Improve corrosion resistance

Silica is composed of silicon dioxide, or silica, which is an inert material. This means that silica does not react with most alkaloids or acids and the silica is evenly distributed on surfaces. In this way, silica powder helps improve cavitation and corrosion resistance 3 to 16 times.

9. Shorten the induction period

Adding silica fume to concrete shortens the induction period and provides early strength.

10. Crack prevention

Silica fume can reduce the peak temperature of the epoxy resin curing reaction. In addition, it reduces the shrinkage rate and linear expansion coefficient of solidified concrete, thereby reducing internal stress and preventing cracking.

11. Improve frost resistance

The relative elastic modulus of micro-silica is only 10 to 20 percent after 300-500 freeze-thaw cycles. Meanwhile, the average elastic modulus of ordinary concrete is 30 to 73 percent after 25-50 cycles. Like this, in concrete Adding microsilica powder can significantly improve its frost resistance.


Buy High-quality Micro Silica Powder at LSFerroalloy

LSFerroalloy is a professional micro-silica powder production and processing manufacturer, engaged in the research and development of high-quality micro-silica powder, and a technology-based enterprise focusing on export. With advanced production and testing equipment, the company strictly follows ISO9001 standards to process, produce, and package multi-purpose micro-silica powder products with various contents and grades. At present, Our company’s production capacity has reached 5,000 tons per month. Buy our high-quality silica powder products now!


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