Summary of Master of Science Thesis
Title: The Classification of Natural Sands to Achieve Optimum Properties of Cement Mortar Roof Tiles
by Ali Meshkot, 1985

Sand may be graded by size by any one of a number of methods which are reviewed in this thesis. The method of representation of the proportions of three different size ranges is discussed theoretically and an experimental investigation into the grading of sand using a flow cone was pursued. Methods were found for representing fineness modulus and specific surface on a triangular diagram.

Experimentally, dried sand was sieved to obtain the percentage of each of six fractions, which were then mixed in pairs to produce three parts.

A flow cone was designed and each part of the sands was put through it yielding flow time and percent solid volume. These factors were compared with values of fineness modulus and specific surface, as calculated from the sand grading. The average particle size of each of the seven sands considered was found to be closely related to their fineness modulus and flow time.

Using these sands, mortar plaques were made with constant water/cement and sand/cement ratios. Their moduli of rupture were found to have 79% correlation with the flow time of the whole sand, and density had an 83% correlation with the solid volume of the whole sand. Therefore the simple flow cone test for sand has been recommended as a possible future test method for density and strength indication of a cured mortar made using this sand. 

Source  http://Ali.Meshkot.com