Describe the advantages of use of fly ash in concrete?

Describe the advantages of use of fly ash in concrete? 

Fly Ash is the product that produce from the combustion of powered coal. In India, fly ash was used for the first time in the construction of Rihand Irrigation Project, Uttar Pradesh in 1962, replacing cement up to about 15 per cent. Advantage: -

• It reduces the permeability.
• Using with fly ash the pore in concrete is also reduced. 
• This increase strength.
• Fly ash particles are spherical and in same size so it reduces the amount of water used for mixing. 
• This can increase workability. 
• It also helps in the resulting in sharp and better surface appearance.
• It gives better workability with less water.
• The reduction of temperature rises for 30% substitution of fly ash.