Author
A.I.G.YOOL AND T.P.LEES Green Land Reclamation Ltd

Abstract
Mortars made with five building sands, with a range of methylene blue values and fines contents, were assessed for durability using a laboratory scale freeze thaw and sulfate attack test. Properties of the plastic and hardened mortar are presented and the nature of the sub 63 um sand fraction of the sands is discussed. Surface area, clay type and clay content of the fines are controlling factors in affecting water demand of the air entrained cement : lime : sand mortars tested. The methylene blue test for clay fines in sand can be used to predict the durability performance of the hardened mortar. For the mortars tested, the water cement ratio of the mortar can be used for the same purpose.