In-plane cyclic behaviour of load bearing masonry walls

An extensive experimental research aimed at defining the mechanical behaviour of hollow clay unit load bearing masonry walls has been recently carried out at the University of Padua. Fifty-one specimens were characterized by means of uniaxial and diagonal compression tests and by means of in-plane cyclic shear compression tests. Three types of masonry walls were investigated, namely masonry made with unit with mortar pocket, masonry made with tongue and groove units, masonry made with unit with small dimensional tolerance in height and thin layer mortar. Based on the experimental results, a numerical research to evaluate the reduction of the elastic response of the masonry walls due to their hysteretic behaviour was carried out. The response of SDOF systems with given ultimate ductility was determined through non-linear dynamic analyses, for a range of natural periods that characterize the elastic phase of unreinforced load bearing masonry buildings. In the present contribution, the results of the cyclic in-plane tests are discussed, and some first conclusions coming from the dynamic analyses carried out are presented.