5 minute Flash. Silica Fume and Fly ash. Mohamed Wagih BU Manager Contractors Sika Qatar. Flash Agenda :. Definition . Specification Standards. Chemical and physical Characteristics. Advantage and Disadvantage of Fly Ash in Fresh and hardened concrete.
Fly ash is a group of materials that can vary significantly in composition. It is residue left from burning coal, which is collected on an electrostatic precipitator or in a bag house. It mixes with flue gases that result when powdered coal is used to produce electric power.
Very fine non-crystalline silica produced in electric arc furnaces as a by product of the production of elemental silicon or alloys containing silicon-ACI 116R-Grey colored powder similar to Portland cement or some fly ash.
Comparison of chemical and physical Characteristics Fly Ash, Silica Fume and Portland cement.
Silica Fume is typically much more reactive, particularly at early ages , because of its higher silicon dioxide content and because of its very small particle size .
Cost of fly ash
Fly ash typically costs approximately 1/2 to 1/3 that of Portland cement as delivered, assuming a suitable means of batching is already in place.
The benefit seen from adding Silica Fume are the result of changes to the microstructure of the concrete.
Even if Silica Fume didn’t react chemically, the micro-filler effect would bring about significant improvement in the nature of the concrete .
Effect of Silica Fume on fresh concrete and how those effects improve constructability and the final concrete.
Effect of Silica Fume on Hardened Concrete and how those effects are used in concrete applications.
By: Eng.:Mohamed Wagih
Business Unit Contractors Manager Sika Gulf B.S.C - Qatar Division
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