Corrosion of steel in concrete - a basic understanding and research needs in Hong Kong

The corrosion of steel in reinforced concrete has recently become a major durability problem of building structures in Hong Kong. According to a survey conducted by the Hong Kong Housing Authority (HKHA), about 50% of its housing blocks have defects of one kind or another needing repair. The range of defects includes different forms of spalling, loss of cover major cracking and loss of cross-sectional area of reinforcement. The article discusses two major forms of corrosion, sodium chloride attack and carbonation attack.