Investigation of movements in block masonry walls

Abstract

One of the main concerns in block masonry is cracking, mainly due to thermal and moisture movement. There are some standards which give guidelines and recommendations to control cracking, but these cannot be directly used for local masonry due to the differences in properties of masonry units used, environmental conditions and the construction techniques. This experimental study is mainly carried out to investigate the extent of movement in block masonry and also to find the influence of mortar mix, initial condition of blocks, type of blocks used and wall thickness on movement in block masonry. Sixteen blockwork panels were constructed to study the selected test parameters on movement in block masonry. The movement was monitored for a period of one year, using dial gauges which were permanently fixed to each panel. From the results, it is found that the movement in block masonry is influenced by the initial moisture condition of the blocks. A significant influence of mortar mix and thickness of wall on movement is not seen from the experimental results. It was observed that the movements reached the maximum values within 8 ~ 9 months after construction of blockwork panels. It is found that the highest shrinkage strain of 0.02% is recorded in the masonry panel constructed with saturated solid blocks and 1: 6 mortar mix.