How many wheelbarrows of cement sand and gravel in a cubic meter of concrete?

35 to 70

It depends on the mix of concrete you are using. A basic 1-2-3 mix is 5 1/2 cubic feet of portland cement (a wheelbarrow, depending on its size, holds 1/2 to 1 cubic feet), 11 cubic feet of sand, and 16 1/2 cubic feet of stone (called aggregate) from 1/2 to 1 inch in size each. To this is added about 12-15 gallons of water.(1 1/2 to 2 cu.ft.). This will make just a little less than 1 cubic meter of concrete.

A weaker mix for basic work not needing structural strength a 1-2-3 mix of 1 part stone, 2 parts cement and 3 parts sand can be used, this would require a bit less than 1 part water.

A stronger mix of 1 part cement, 1 1/2 parts sand and 3 parts stone with about 1/2 part water is good for heavy duty concrete work. Stone will increase the strength of concrete and sand will weaken it. Using too much or too little water in the mix will weaken it as well. Additionally, concrete with too much water or too little cement tends to shrink and crack as it sets. The amount of water to use is mainly dependent on the cement in the mix. There should be at least half as much cement as sand in any mixture. The amount of stone to use should be between 1/4 and 3/4 of the total mixture. Grouts and mortars use no stone and may add limestone as an additional binder. These should not be used for structural concrete, but can be used for foundation pointing, bolt anchoring or mortaring brickwork.