The effect of unit water absorption on long-term movements of masonry

Abstract

Long-term movements in masonry can be predicted by composite modelling, however, the accuracy of prediction is reduced if the unbonded brick and mortar phases do not reflect the behaviour of the bonded components. It is apparent that the water absorbed by the unit soon after laying produces changes in the behaviour of the bonded components of the masonry especially of the mortar joints, which have reduced creep and shrinkage. This paper presents a study of the transfer of moisture between the brick and mortar components from 30 min after laying of bricks to 120 days. Subsequently, unit water absorption modification factors are developed which improved the accuracy of predicting creep and moisture movement strain of masonry by composite models to within 10% of the measured values