Mix ratio for filling blocks All manner of questions and solutions to problems and issues surrounding the subject of brickwork, blockwork and stonework

[russ01]

I have foundation walls built from 12"x16"x8" to hold a 12'x14' wooden shed. I want to fill the block with concrete. I'm mixing my own concrete but dont know how strong to make the mix. What ratio of sand, cement, water should i use for the mix for filling the block?

Thanks