Corrosion behaviour of metal inserts in simulated ancient masonry mortars

Corrosion of metal inserts may be detrimental to the durability of masonry. The paper discusses corrosion of carbon steel, stainless steel and titanium embedded in aerial and hydraulic mortars simulating those of ancient walls. The effects of temperature (5-40°C), moisture (65-95% RH and water suction) and electrical resistivity of mortars on the corrosion of metal inserts are discussed. Results showed that the corrosion rate of embedded steel, regardless of the mortar composition, is negligible in mortars exposed to 65-80% RH (even at 40°C) and modest even at 95% RH, while high values were obtained in the presence of water uptake.