Three-leaf brick masonry walls : the scale factor

A wide number of European historic buildings has their own structure constituted by multiple-leaf masonry walls that represent a challenge issue, considering their mechanical behaviour [1-4]. This study aims to characterize three-leaf masonry structures (non-injected and injected with a lime-based grout) to predict their mechanical behaviour under compression loads. Results of experimental tests on three-leaf brick masonry panels and numerical finite element models are critically compared. The numerical modelling simulates masonry panel cross section through 2D plane strain models; masonry mechanical behaviour is analysed at different scales: the scale of the experimental panels and the real size of the historical buildings walls. An investigation of different wall dimensions allows taking into account the difference by experimental results and effective conditions to propose a better interpretation of the experimental data based on the scale factor. A method to predict the mechanical behaviour of three-leaf masonry structures before and after consolidation by injection of a lime-based grout is presented and discussed, in order to formulate a simplified evaluation of existing structures in multi-leaf masonry.