Experimental Investigation on Masonry Reinforced by Bed Joints Structural Repointing and Plating System

Strengthening of damaged masonry walls is an important aspect during building retrofitting operations. Innovative materials, as textile composites e.g. FRP (Fiber Reinforced Polymer), FRCM (Fiber Reinforced Cementitious Matrix), SRG (Steel Reinforced Grout), TRM (Textile Reinforced Mortar) can be used, in order to repair and strengthen either modern and historic constructions. However, these materials cannot be applied to masonry façades or elements with facing bricks because violate the aesthetic and conservation requirements. A recent technology, called reinforced repointing technique, have been developed being minimally invasive and respectful of the aesthetic of the fair – faced masonry elements. It involves the application of materials having high tensile strength such as reinforcing steel bars, steel textile sheets or composite thin pultruded laminae with crack arrestor function, to reduce the vulnerability of masonry structures against in-plane actions. The main advantages of reinforced masonry are: compressive strength and ductility are increased, pseudo-vertical cracks are contrasted as well as the original aesthetic aspect of the masonry is saved being the strengthening materials embedded in the joints. Many of the studies in literature deal with experimental and/or numerical investigations conducted on undamaged masonry specimens. Nevertheless, the assessment of the mechanical behavior of reinforced masonry structures in their on-site conditions is fundamental for understanding the role of the reinforcement. In such a context, this work presents the results of an extended experimental campaign conducted on undamaged and damaged masonry specimens, strengthened by using reinforced repointing technique and FRCM system. Also numerical and analytical models have been used to support and foresee the experimental results.