ROB VAN DER PLUIJM, HARRY S. RUTTEN, AND COR S. SCHIEBROEK Eindhoven University of Technology
The main variable in the experimental research with masonry wallettes tested in flexure, was the angle between bending axis and bed joints. Two types of widely used masonry in the Netherlands were tested, fired clay bricks with normal joints (12.5mm general purpose mortar) and calcium-silicate elements with thin layer joints (3mm ready mixed special purpose mortar). The main goal of the tests was the collection of data consistent with micro tensile and shear tests carried out earlier. The data will be used to verify a model for masonry in flexure that is currently being developed. For the fired clay masonry four different angles and for the calcium silicate masonry three different angles were used. The strength and behaviour in these directions is compared and related to tensile bond tests. Comparison of the results of specimens with clay brick and calcium-silicate masonry bent horizontally and vertically has shown that the decrease in stiffness visible in the moment-curvature diagram of the specimen bent horizontally, was caused by cracking of the head joints. This type of behaviour, found in specimens bent in other directions, may also arise pom (micro)-cracking due to complex stress combinations in the joints. The flexural strength in the horizontal direction could be related to the flexural strength of the units.