for patio what ratio cement +sand+gravel
A properly designed concrete mixture will possess the desired workability for the fresh concrete and the required durability and strength for the hardened concrete. Typically, a mix is about 10 to 15 percent cement, 60 to 75 percent aggregate and 15 to 20 percent water. Entrained air in many concrete mixes may also take up another 5 to 8 percent.
I use a 5 to one ratio (five parts gravel, one part cement) the gravel is 60/40 (I assume that is 60 percent sand, 40 % rocks) The moisture content of gravel varies, so difficult to give amount of water.
