One of the most heterogeneous items used in the construction sector is concrete. The major ingredient required for making concrete is cement but its hackneyed usage marks to be a serious environmental concern. This issue could be addressed by seeking the help of novel imperative cementing materials and microsilica proves to be one such alternative. Microsilica, otherwise known as Silica Fume is an exquisitely fine polymorph of silica in amorphous form. It unfolds as a by-product when ferrosilicon alloys or silicon metals are produced using electrical –arc furnaces. It is essentially silicon dioxide (greater than 90%) in a non-crystalline shape and is understood for possessing cementitious and pozzolanic properties as well. The components such as oxides of aluminum, calcium, iron, magnesium, potassium, and sodium alongside sulphur and carbon constitute the remaining part of the microsilica. Found in spherical shapes, microsilica is further processed to get rid of impurities and also to regulate the size of the particles. The average diameter of silica fumes ranges from 100nm to 200nm. Microsilica is durable and tends to supply great resistance against steel corrosion.
Microsilica, when used as an admixture to concrete, provides a high pozzolanic effect and can be used as a concrete additive for various purposes.
The application of microsilica in tunneling operations is admired in several ways, the most popular application being shotcrete. Known as mortar or air-blown concrete, shotcrete is a type of concrete conveyed aerially onto a surface with great pressure and velocity using pipe and hose. This enhances the resistance to the erosive process by water in wet areas and marine construction. It is typically used on uneven and rough surfaces such as swimming pools, underground tunneling and retaining walls, etc. It is most commonly used for slope protections and places where normal concrete cannot be applied.
The usage of micro silicon is highly appreciated where resistance to certain factors proves to be an excellent deal. Few instances where microsilica acts as a savior are included –
Refractory materials generally use unencrypted silicon fume powder to increase their strength. Microsilica can be used to elevate the liquidity of fluid refractory materials thereby reducing water consumption. Having solid hydrophilic, microsilica can also help achieve strong cohesion in refractory materials, thus improving the resistance performance concerning high temperature.