Fly ash, which is a by-product of the coal combustion, is used recycled in the making of concrete. What advantages is / are offered by Fly ash concrete in comparison to concrete made with only cement?
1.It saves water
2.It lowers heat of hydration
3.It reduces the corrosion of steel
4.The concrete quickly becomes strong
Choose the correct option from the codes given below:

Answer: [D] 1, 2, 3 & 4

Flyash is one of three general types of coal combustion byproducts (CCBP’s). The use of these byproducts offers environmental advantages by diverting the material from the wastestream, reducing the energy investment in processing virgin materials, conserving virgin materials, and allaying pollution. Although flyash offers environmental advantages, it also improves the performance and quality of concrete. Flyash affects the plastic properties of concrete by improving workability, reducing water demand, reducing segregation and bleeding, and lowering heat of hydration. Flyash increases strength, reduces permeability, reduces corrosion of reinforcing steel, increases sulphate resistance, and reduces alkali-aggregate reaction.  Flyash reaches its maximum strength more slowly than concrete made with only portland cement. The techniques for working with this type of concrete are  standard for the industry and will not impact the budget of a job.

This question is a part of GKToday's Integrated IAS General Studies Module