Fly ash is one of the residues generated in combustion, and comprises the fine particles that rise with the flue gases. Ash which does not rise is termed bottom ash. In an industrial context, fly ash usually refers to ash produced during combustion of coal. Fly ash is generally captured by electrostatic precipitators or other particle filtration equipments before the flue gases reach the chimneys of coal-fired power plants, and together with bottom ash removed from the bottom of the furnace is in this case jointly known as coal ash. Depending upon the source and makeup of the coal being burned, the components of fly ash vary considerably, but all fly ash includes substantial amounts of silicon dioxide (SiO2) (both amorphous and crystalline), being endemic ingredients in many coal-bearing rock strata.
Advantages to Fly ash
Greater long term strength
Improve Workability
Excellent Thermal Insulation
Reduce Permeability
Low heat of hydration
Increased sulphate resistance
Increased corrosion resistance
Reduced Alkali - Aggregate Reaction
Fly ash is very good resource material. It can advantageously used in cement and concrete works as well as fill applications. Flyash is transported to fly ash storage silo. Fly ash is loaded in close tankers and transported to RMC plants. Fly ash is also available in bags.
Portland cement when mixed with water produce cementitious material in this process free lime is also liberated. This free lime cause of porosity in concrete, however if fly ash available in the mix, free lime will reacts with fly ash to produce additional cementitious materials which produce additional strength and make the concrete denser, thus increase its durability, the present of fly ash also helps reducing heat of hydration.
FLYASH Applications
Ready Mix Concrete
Plain and Reinforced Concrete
Plastering and Brick Mortar
General Structural Concrete
Pumpable Concrete
Self-compacting Concrete
Pre-Cast Concrete
Mass Concrete