Synergic effect against corrosion between galvanized steel rebars and hydrophobic concrete

The influence of silane-based hydrophobic products, used as concrete chemical admixtures, on the corrosion resistance of concrete specimens reinforced with galvanized steel plates was studied. Sound or deliberately pre-cracked concrete specimens, with crack 0.5 or 1 mm wide, were manufactured with w/c ratios 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 solution. The results, in terms of water absorption tests and electrochemical measurements, showed that the hydrophobic concrete protects galvanized steel reinforcement from corrosion even in the presence of cracks in the concrete cover, especially when high w/c ratio is used.