SikaFume®-50 S when added to concrete changes the rheology and reacts with the cement hydration products to dramatically improve concrete strengths, durability and impermeability, allowing concrete to be used in environments where performance demands are high.
The power behind the performance
Key to the performance of any concrete is the inclusion of admixtures in its mix design. SikaFume®-50 S is a concrete additive based on silica fume technology.
It is a mineral admixture composed of very fine solid glassy spheres of silicon dioxide. It is a by-product of the industrial manufacture of ferrosilicon and metallic silicon in high-temperature electric arc furnaces. Silica fume particles have a diameter of less than 1μm; about 100 times smaller than the average cement particle.
The Pozzolanic and micro-filler effect of SikaFume®-50 S improves many properties of concrete helping with its durability including:
Concrete containing silica fume has very high abrasion resistance. In floor and pavement construction it increases durability in high-traffic areas. Its use saves money and time and improves operational efficiencies for the facility operator.
Compressive strengths are dramatically increased for high performance concretes. SikaFume®-50 S in conjunction with Sika superplasticisers are used to produce very high strength concrete. It is also much easier to pump concrete up the high-rise buildings during construction.
The reduced permeability of silica fume provides protection against intrusion of chloride ions, thereby making it ideal for applications where concrete will be required to resist chemical attack.
Sulphate and chemical resistance
Concrete containing silica fume has a low penetrability and high chemical resistance that provides a higher degree of protection against sulphates.
Decreased permeability gives the concrete excellent freeze-thaw resistance because less water is trapped inside the cement paste.
A higher rate of loss of heat from the outer surface of concrete causes cracking. Cracking is dangerous due to many reasons like reduced strength and reduced durability. Replacing cement with silica fume and observing the efficiency factor of silica fume, a lower maximum temperature rise and temperature differential will take place for concrete with the same strength.