Moisture transfer through mortar joints: interface resistances or hygric property changes?

This paper investigates the deviating hygric behaviour of mortar joints, based on a combination of hygric property measurements, numerical simulations, sharp-front analysis and microscopic imaging. Comparison of the hygric properties of mould and joint mortars reveals significant differences. Further analysis with numerical simulations indicates however that an interface resistance must be attributed to the brick-mortar bond plane, which is further corroborated by sharp-front analysis of free water uptake in masonry samples. While the deviating hygric behaviour of mortar joints previously has been ascribed to hygric property changes or interface resistances, the current study points out that both are at play, and it demonstrates the influence of the curing conditions on these phenomena.status: publishe