Application of Nano-Silica in Cement Materials
Key words
Nano silica, concrete, C-S-H gel, cement
Nano-silicon dioxide is an inorganic chemical material, commonly known as silica.
Overview
Ultra-fine nano-scale, with a size range of 1~100nm, has optical properties of anti-ultraviolet, and can improve the anti-aging, strength and chemical resistance of other materials. Very versatile.
Nano-scale silica is amorphous white powder, non-toxic, odorless, non-polluting, microstructure is spherical, flocculent and reticular quasi-granular structure, insoluble in water.
Chemical
CAS No.: 60676-86-0
Molecular weight: 60.08
Molecular formula: SiO2
Application
sealants, adhesives
The addition of nano-SiO2 coats a layer of organic material on its surface to form a network structure and form a silica structure, making it hydrophobic, which can inhibit the flow of colloids, accelerate the curing speed, improve the bonding effect, and increase the sealing of the product. properties and impermeability.
Application advantages
The incorporation of nano-silica into cement-based composite materials can not only promote the cement hydration process and increase the hydration products, but also fill the fine voids in the material, making the material more compact, thereby improving the structural properties and durability of the material. It can also effectively improve the compressive strength, flexural strength and fluidity of the material.
The use of nano-silica to replace part of the ordinary concrete mix, thereby improving the performance of concrete. It is easy to form chemical bonds with hydration products in cement stone to produce CSH gel, which can greatly improve the physical and mechanical properties and durability of cement paste.
Performance advantage
Incorporating nano-silica into cement mortar can improve the compressive and flexural strength of cement mortar at all ages.
It can reduce the slump and expansion of concrete.
It can increase the self-shrinkage strain of concrete; improve the anti-Cl-permeability and anti-freezing durability of concrete.
