How hard can it be to mix four ingredients to produce a stated outcome? aggregate, cement, water and an admixture (or two) We have probably done three of them around the house with a shovel and a board. I once made a whole patio of slabs with my own formwork with embedded red chips floated into the surface. and the real reason for doing it was to prove a mason wrong, whilst having a pint with him he declared, you will never make them frost resistant! Want a bet, I internally cogitated? I was impressed one of his durability factors …