Is it appropriate to add fly ash to the cement and water slurry for cellular concrete?
Fly ash added to the cement does not adversely affect the basic hardened state of cellular concrete. Infusing and supporting the cellular concrete with the air cell system is a mechanical action and is not problematic with fly ash or admixture concrete chemistry. Note that some fly ash mixes may take longer to set than pure portland cement applications. Mixes with large percentages of fly ash may take an very extended time to set up. High carbon content fly ash such as typical “bottom ash” should be generally avoided in most cellular or plain concrete mixes.
