Strength, bond and durability of stainless steel reinforced grout

Steel Reinforced Grout (SRG) is an effective, cost-efficient and versatile technology for strengthening existing structures. However, the high strength properties exhibited by steel textiles can rarely be fully exploited in design, due to the premature occurrence of bond failure and deterioration. Because of the small diameter of steel cords or wire ropes, and the alkalinity and vapour permeability of the inorganic matrices, the long-term effectiveness can be affected by the combined action of the salt and alkali attack. Although largely overlooked, the use of stainless steel can be a breakthrough for this technology. This work presents the first comprehensive characterization of a Stainless SRG system (SSRG) with a lime-based matrix. Its tensile strength, bond capacity, pullout behaviour and durability against various ageing conditions were investigated, and design parameters were determined. According to test results, stainless steel combined with lime mortar has excellent mechanical properties and durability, making it the most appropriate solution for the long-lasting strengthening of masonry structures.