Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32 – 20133 Milan, Italy
The numerical modeling of the time evolution of stresses and strains in brickwork made with Calcium Silicate (Ca2SiO4) units under sustained loads is dealt with, within the framework of linear viscoelasticity. The research investigates the influence of the brick pattern on the creep behavior (global deformation; stress redistribution) of any wall under typical load conditions, and assesses whether a simplified 2D layered model can be employed to get reliable predictions. To this end, finite element analyses were carried out, using two 3D models representative of header bond masonry and Flemish bond masonry; the results were compared with those given by the layered model. The influence of the mortar properties on the stress redistribution was also investigated. Whereas the layered model provides a fairly good prediction of the global creep deformation for both masonry formats under vertical (uniform and eccentric) load, it cannot be applied under more complex load conditions. Under uniform vertical load, 3D models taking the real masonry bond pattern into account must be used to predict the local stress evolution accurately. The uncertainties regarding the mortar Poisson’s ratio affect the time evolution of the transverse stress in the units and the joints.
Masonry, creep, linear viscoelasticity, header bond, Flemish bond