Masonry in Compression: Deformational behaviour due to brick mortar interaction

This work focuses on the role of the brick-mortar interaction in masonry under compression. The mortar joint, as an interface between units, is formed during the brick laying process and positioning of the unit and usually acts as a weak spot. The program with over 200 tests included six clay-brick types and multiple mortar mix designs. Material properties were derived which can be used in numerical simulations and trends were established. Crack development processes were recorded and post peak behaviour observed. The brick-mortar interaction was measured and visualized with novel experimental research techniques such as ESPI - a laser speckle instrument - and a movable seating arrangement. ESPI was used to investigate the effect of joint thickness and pointing. Clearly the shape of the bed joint affects the strain distribution over the joint and showed that rotation occurred in the brick-mortar interface, due to the shape of the bed joint. This study confirms the important role of the brick mortar interface.