Determination of Chloride Content in Hardened Concrete

Slow Corrosion Processes Within a Structure

Chloride, often present in large quantities in de-icing salts, primarily reaches concrete surfaces during the winter months through salt spreading. Over time, the chloride penetrates deeper into the concrete element and can eventually reach the reinforcement steel inside, where it can cause significant damage. Chloride destroys the passive layer (protective coating) of the steel, making it vulnerable to corrosion. Chlorides in concrete therefore pose a threat to the load-bearing capacity of supports and walls in parking garages and bridges, often necessitating the repair of reinforced concrete. Key factors include the type and quality of the concrete and the amount of chloride that has reached the reinforcement.