J. J. BROOKS and P. R. B1NGEL Leeds Polytechnic

One-year data are presented for horizontal and vertical moisture movements of unrestrained walls and piers built from two weeks old Fletton bricks. Whereas horizontal movements are small, vertical expansions occur after approximately three months of exposure, the expansions being much greater for a single-leaf wall than for a solid pier. The behaviour is similar to that reported earlier for older Fletton brickwork, and depends on the ratio of volume to exposed surface area of the brickwork. The level of vertical expansions cannot be explained in terms of individual brick expansion and mortar shrinkage alone, nor in terms of sulphate expansion of mortar or brick.