this sand was composed of particle sizes ranging from 3 mm (1/8") to 0.074 11511(1/320") with
a grading curve ranging from 100% passing ASTM sieve number 8, to 5% passing ASTM sieve
number 100. The use of a pozzolan to improve the sulphate resistant qualities of the
cement mortar was considered, however no diatamaceous earth or similar natural pozzolan
was available and the industrial fly ash which wae procurable proved to have too high
a sulphur content, with consequent injurious results on setting times and strength
Properties of the mortar.it was considered that the modified type II Portland cement
was sufflcienly sulphate resistant for the purpose, although a type V Portland cement,
if available, would provide additional resistance against sulphate attack