SRG Composite Systems for Strengthening Masonry Structures: From Laboratory to Field Applications

The use of Fiber Reinforced Polymer/Grout (FRP/G) composites for the external strengthening and repair of masonry structures has met over the years an increasing consensus at both the academic and industrial levels.

One of the most promising systems consist of Ultra-High Tensile Strength Steel galvanized micro wires twisted in cords or ropes, assembled parallel to each other to form unidirectional fabrics. Steel textiles can be externally bonded to the substrate via wet lay-up, by using either epoxy resin/mineral mortar, obtaining a composite known as Steel Reinforced Polymer/Grout (SRP/G). The inorganic matrix offers several advantages such as a great reduction in material costs, an higher vapour permeability and resistance to high temperatures as well as a much higher compatibility without compromising bond with the substrate and overall performance. A number of research studies have been carried out on SRP and SRG systems in the last fifteen years. Fundamental mechanical properties, durability and shear bond performance on masonry substrates have been investigated through tests on small- and medium-scale specimens (panels, brickwork pillars and masonry arches). These studies have shown that SRP and SRG are an effective, durable and cost efficient solution for the externally bonded reinforcement of structures. This paper briefly introduces to the main properties and mechanical characteristics of steel fibers, presents few research results of tests performed on real scale structural members (walls, arches) and introduces some case studies on masonry structures demonstrating the different field applications of this new and effective strengthening solution.