Retrofitting of masonry walls by using a mortar joint technique; experiments and numerical validation

Abstract

This paper presents research on a conventional but practical retrofitting method for masonry walls along with the numerical modelling of it under in-plane lateral shear–compression loading. The latter is capable of predicting the experimental collapse load and overall behaviour quite accurately. The retrofitting approach is based on building a wall parallel to an existing single-leaf wall and bonding the two leaves together using a mortar (collar) joint, merging the two individual panels into a unified double-leaf wall. Experiments on this retrofitting approach for both undamaged and damaged masonry walls have been introduced in the present paper. The tests revealed that the pre-damage application can increase the strength by 50% while the post-damage one can restore the initial strength. A micro-scale numerical model has been devised by considering the bricks as rigid elements and the mortar joint as a nonlinear failure surface. The model was implemented in the commercial Finite Element (FE) software MIDAS FEA and the numerical results were verified against the available experimental data.