In the process of concrete preparation, in order to meet the strength requirements of the project, silica fume is usually mixed into it to meet such requirements. As a by-product of ferrosilicon smelting, silica fume is mainly obtained from smelting soot trapping and cooling, how does silica fume improve the strength of concrete? What is the principle?
The principle of silica fume to improve the strength of concrete
Particle filling effect
Silica fume has a finer fineness than cement particles, the vast majority of particles less than 1μm, the average particle size are in 0.1 to 0.3μm, is one percent of the size of the cement particles, so after mixing into the concrete, can effectively fill the cement pores, so that the concrete slurry more dense, thereby increasing the degree of dense concrete and improve the strength of concrete.
Secondary hydration effect
The main component of silica fume is SiO2, which can produce secondary hydration reaction with calcium hydroxide produced by cement hydration in concrete mix, forming calcium silicate gel, which can improve the strength of concrete after hardening, and also make a large number of pores in concrete disappear, reduce the content of calcium hydroxide, greatly reduce the concrete carbonation defects, and improve the impermeability and durability performance.
Silica fume use precautions
The amount of silica fume should not be mixed with more
Because the silica fume particles are very small, so the specific surface area is very large, about 80 to 100 times that of cement, has a strong water absorption, in the concrete will emit more heat of hydration, easily lead to shrinkage joints later, so the amount of blending is generally between 3% to 10%, according to the specific proportion of the experiment to determine.
Efficient water reducing agent should be used
Concrete simply mixed with silica fume will lead to an increase in water demand, so that the original water-cement ratio changes, affecting the performance of concrete, so it should be combined with the addition of high-efficiency water reducing agent, so that the concrete in the case of a certain water-cement ratio, mixed with silica fume to improve its strength.
About how silica fume can improve the strength of concrete, through the above-mentioned content can be seen mainly physical and chemical two effects, and want to use silica fume to improve the strength, but also need to ensure the fineness of silica fume and SiO2 content, so you should use quality assurance of silica fume products.
High Quality Silica Fume Supplier
Henan Superior Abrasives (HSA) has been a global supplier of high-quality silica fume since 2001. We have established long-term and stable cooperation with many concrete construction companies around the world to provide our customers with high-quality silica fume with different contents and different uses, fully satisfying all kinds of concrete project needs.
If you have any needs for silica fume, please feel free to contact us!
- WhatsApp:+86-18638638803
- Email: sales@superior-abrasives.com
- Address: No.68 Zhengtong Road, Zhengzhou, Henan, China
