As a concrete pozzolan fly ash was never ideal.
Replacement of cement by fly ash in concrete.
But it was cheap the by product of burning coal and within a restricted class type class f effective.
In some cases fly ash can add to the concrete s final strength and increase its chemical resistance and durability.
The future of fly ash as a readily available and quality effective concrete pozzolan is murky and troubled.
Fly ash can significantly improve the workability of concrete.
In 2005 acaa.
Reinforced cement concrete code of practice fly ash conforming to is 3812 part 1 up to 35 can be used as part replacement of opc in the concrete.
The paste is the key to strong and durable concrete assuming average quality aggregates are used.
At full hydration concrete made with regular cements produce approximately 1 4 pound of non durable lime per pound of cement in the mix.
Recently techniques have been developed to replace partial cement with high volume fly ash 50 cement replacement.
Why should you consider fly ash concrete.