Innovative masonry strengthening techniques maintaining the original brickwork appearance: An overview

In many seismically active regions, historical masonry buildings represent a significant portion of the building heritage. These structures very often are characterised by masonry that presents low mechanical properties, due both to its texture and to the bad mechanical characteristics of the mortar. If we want to preserve this heritage the use of strengthening methods is necessary and, consequently to an increasing interest in the conservation of historic construction, the interest in new strengthening techniques is nowadays greater. In fact, in the past, “conventional” techniques-as grout injections or concrete external reinforcement – were more common, but these systems have shown problems over time in terms of effectiveness and durability. Recently new reinforcement materials were introduced to the world of restoration like Fibre Reinforced Polymers (FRP) or Fibre Reinforced Cementitious Matrix (FRCM), which are made of synthetic fibres embedded in resins or mortar, respectively. However, where maintaining the original aspect of the facing-masonry is essential, all the previous techniques seem to be unsatisfactory. In this paper, is presented a review of the innovative techniques that have been recently proposed to solve this problem, in order to facilitate the role played by designers in restoration and rehabilitation interventions.