Analysis of the cost of construction of a concrete slab in ...
Nov 11, 2013· A concrete ratio of 1 to 2 to 4 for cement, sand and ballast produces a much stronger class 20 concrete, mostly used for suspended slabs, beams and columns, which are self supporting. In Kenya, the fundis and contractors mix 1 bag of cement to 3 wheelbarrows of sand to 4 wheelbarrows of ballast.