Class F fly ash is designated in ASTM C 618 and originates from anthracite and bituminous coals. It consists mainly of alumina and silica and has a higher LOI than Class C fly ash. Class F fly ash also has a lower calcium content than Class C fly ash.
Replacement
When used in portland cement, Class F fly ash can be used as a portland cement replacement ranging from 20-30% of the mass of cementitious material.
Advantages
When used as a portland cement replacement, Class F fly ash offers the following advantages when compared to unmodified portland cement:
Increased late compressive strengths (after 28 days)
Increased resistance to alkali silica reaction (ASR)
Increased resistance to sulfate attack
Less heat generation during hydration
Increased pore refinement
Decreased permeability
Decreased water demand
Increased workability
Decreased cost ($80/ton for portland cement vs. $30/ton for fly ash).
Fly ash, also known as flue-ash is a residue which is generated during combustion and consists of fine particles. There are impurities in coal which mostly consist of clays, limestone and dolomite particles. These turn up into ash as they cannot be completely burned.
Fly ash is useful in a number of ways and is one of the most researched upon mineral source. It is mainly a pozzolanic substance which contains aluminum and silicon material which in return due to the presence of water can take form of cement.
A lot of research and development initiative have been taken place across the globe to build and develop technologies that can utilize the full potential of fly ash. Royal Mineral takes care to ensure flawless production stages.
Fly ash is a by-product of coal burning at the utility plants. As coal is burned, non-combustible mineral impurities in coal evaporate andcondense into tiny particles of glass, almost totally spherical inshape. The individual particles are very small, like talcum powderand are carried up and out of the boiler in the flow of exhaust gasesleaving the boiler after the coal is consumed.
The fly ash particlesare removed from the exhaust stream in bag houses or electrostatic precipitators and then stored for later shipment
The difference between fly ash and Portland cement becomes apparentunder a microscope. Fly ash particles are almost totally spherical inshape allowing them to flow and blend freely in mixture. Thatcapability is one of the properties making fly ash adesirable admixture of concrete.
Fly Ash is a fine, powdery byproduct produced form burning pulverized coal in thermal power plants for producing electricity. It primarily consists of silica, alumina and iron oxide. Due to its pozzolanic properties. Fly ash is widely used in making concrete, blocks, bricks, and road base materials. It enhances workability, durability, and reduce water consumption. Using fly ash helps in waste management and reduces pollution.
Applications
Fly Ash used as a Pozzolana in Cement, Cement Mortar and Concrete and as an admixture in Mortar and Concrete/ as a part of cement replacement.
1) Cement Production
2) Ready Mix Concrete
3) Self- Compacting Concrete
4) Mass Concrete
5) Roller Compacted Concrete
6) Lightweight Concrete
Coal Fly Ash
CFA could be used in huge quantities in two areas: ash dyke construction and low-lying region filling [26,27,28]. In several affluent countries, CFA has been utilized successfully as a structural filler.
