Bed joint reinforcement and the shear capacity of masonry beams

The design of reinforcement in masonry beams is strait forward. A few, relatively small diameter bars in one or two bottom layers is often sufficient to form a tie while in the masonry compressive struts develop. In the layers further away from the tensile area, often reinforcement is applied with the idea that this decreases the risk of crack development and might increase shear capacity. Masonry beams with a height of 490 mm, 550 mm or 625 mm and a span of 1400 mm, with and without extra bed joint reinforcement were tested. The results of these tests are presented and the effect of the extra reinforcement on shear capacity discussed.
In a number of cases, bed joint reinforcement with a closed hoop configuration was applied. Extra reinforcement did not always increase shear capacity; on the contrary, the capacity was sometimes smaller because the extra reinforcement affected the capacity of the compression struts negatively.