On-site testing of masonry shear walls strengthened with timber panels

The effectiveness of a method to strengthen/repair unreinforced masonry (URM) by using timber-based products was investigated through experimental in situ testing. The strategy consists of timber-based panels connected to the masonry by means of screw fasteners. URM piers obtained from a century-old building were subjected to in-plane semi-cyclic quasi-static loading in as-built, repaired and retrofitted configurations. The application of the reinforcement on previously damaged piers led to a notable increase in the in-plane capacity while the initial stiffness of the repaired specimens was found to be consistent with that of the specimens tested as-built. When applied to undamaged masonry, the retrofit system allowed an in-plane force 40% higher than the capacity of the unreinforced walls, with the initial stiffness comparable with that of the repaired specimens. Both repaired and retrofitted specimens exhibited remarkable displacement capacity (drift levels > 2.0%) and energy dissipation.