In recent years, there has been a great interest in improving the properties of concrete by involving various puzzolanic materials in the concrete mix.
One of these materials, silica fume is receiving much attention because of its favorable contributions to Portland cement concrete properties.
Silica fume is a byproduct from the production of ferrosilicon and silicon metal in an electric arc furnace. This byproduct is generally composed of more than 90% silicon dioxide and may contain traces of other oxides, depending on the furnace charge and the silicon metal being produced.
Portland cement (Type2 laboratory blend)
HRWRA (High range water reducing admixture)
Water reducing set-retarding admixture
Air entraining agent (5% vinsol resin)
Aggregate (Local natural aggregate)
Add mix retardant and HRWRA to the mix water.
Add the mix water containing mix retardant and HRWRA to the mixer.
Add aggregate, cement, and silica fume which should be added early in the mixing process to ensure proper wetting.
Mix for 3 minutes.
Wait 2 minutes to avoid false set.
Add air entraining agent if desired and mix for 2 minutes.
Silica fume if added to the Portland cement concrete provides the benefits such as increased strength, increased freezing and thawing resistance, increased abrasion resistance.
Kit required to develop Silica Fume Concrete: