According to Ken Malone of Texas- Getting your hands on fly ash is difficult unless you buy a semi load. I have e-mailed Home-depot and Lowe's home offices to encourage them to handle fly ash in sack and bulk containers for us "do-it yourself to get it right" people. Fly ash is a super product that the concrete industry wants to remain a secret. .Prof.PK MEHTA encourages using 55-45% fly ash to cement for super strength concrete WITHOUT rebar and 70-30% mix for soft, pliable concrete. No wonder they want it kept quiet!