The effect of silane-based hydrophobic admixture on corrosion of galvanized reinforcing steel in concrete

摘要

Sound or deliberately pre-cracked concrete specimens, with 0.5 or 1 mm wide crack, were manufactured with water to cement ratios (w/c) of 0.45 and 0.75, both in the presence and in the absence of a silane admixture. The specimens were exposed to wet-dry cycles in a 10% NaCl aqueous solution. The results, in terms of electrochemical measurements, and visual and metallographic observations carried out on the galvanized steel reinforcement removed from the specimens, showed that the hydrophobic concrete is able to protect galvanized steel reinforcement from corrosion even in the presence of cracks in the concrete cover, especially when a high w/c is used.