Victoria Fernandes (2002)
Good quality sand is available in developing countries but is in short supplyand is expensive due to the high transportation costs. Poor quality sand, which consists of a significant proportion of clays and silts and is poorly graded, is readily available but needs to be improved if it is going to be used for building with.
It was discovered that when the seven day dry compressive strength tests of comparable concretes with identical water-cement ratios were measured, the strength of the concrete unexpectedly increased as the fraction of fines in the concrete increased. It was discovered that despite the suitable dry compressive strength of the material with a large number of fines, that the use of this material will be hindered due to its large cyclic movements and drying shrinkage.
This type of sand is only suitable for concrete and mortars in unconstrained applications such as block making and lintels and in situations where the material does not undergo cyclic movements, such as non water-proof rendering