Edinburgh Napier University

  Studies have found that over 80% of total water ingress occurs at the brick/mortar interface and not through the brick unit or the mortar. The interface between the brick and mortar is influenced by the tensile bond strength between the two, which is highly affected by the applied load on the structure. However, numerous and often innovative laboratory testing techniques have been developed to assess water ingress under realistic weather conditions, but they consider only unstressed panels. One of the main objectives of this paper is to identify how crucial is the changing of loading direction and applied stress level on the formation of cracks and eventually on water ingress at the brick/mortar interfaces in masonry walls. The paper also presents some of the results from a research program carried out recently on stressed brickwork masonry, which shows that stressing has a fundamental and quantifiable effect on controlling water ingress