Why Is Fly Ash Put in Concrete? | eHowNearly a third of the fly ash produced in the United States is used as a replacement for carbon-dioxide-producing Portland cement in concrete.fly ash how to add to concrete,fly ash how to add to concrete,Using Fly Ash in Concrete - GreenBuildingAdvisorJun 1, 2009 . When portland cement cures, it leaves behind some hydrated lime. Adding fly ash or another pozzolan allows that lime to cure as well (as in the.
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