Structural Investigation of Hong Kong’s ageing public rental buildings

The Hong Kong Housing Authority (HKHA) maintains a stock of over 1000 reinforced concrete domestic buildings of 7 to over 40-stories, providing homes to about 680,000 families. HKHA launched in 2005 a comprehensive structural investigation programme to look into the structural conditions of the older buildings and to establish what needs be done to better sustain them. This paper describes the investigation methodology adopted and some of the findings of the investigation of the first batch of about 80 buildings. The significance of chloride contamination in relatively porous concrete and of moisture in the concrete of these old buildings and the sources of contamination, in particular sea water used for toilet flushing, are discussed.