Non-linear Behaviour of Masonry under Tension

For the micro-modelling of masonry in numerical programs that take non-linear behaviour into account, a complete description of the behaviour of masonry components has to be available. "Complete" means that, apart from the initial stiffness and the strength, the behaviour beyond the peak in the .. diagram is described. This article gives an overview of deformation controlled tensile and flexural tests that have been carried out since 1990 by the author to establish the behaviour prior and beyond the maximum load under tension. All tests were carried under a monotonic increase of a deformation measured on the specimen itself. The behaviour of units and mortar-joints under tension showed a great similarity to that of concrete. Experience in describing the non-linear behaviour of concrete under tension could be applied to the masonry components. The mode I fracture energy of units is of the same magnitude as that of concrete. The mode I fracture energy of mortar-joints is approximately one order of magnitude smaller and showed a great scatter.