Corrosion assessment of reinforced concrete elements of Torre Velasca in Milan

An assessment of corrosion conditions, aimed at the detection of the most suitable intervention method, of the reinforced concrete elements of Torre Velasca, which, from the late 1950s, characterises the skyline of the city centre of Milan, was carried out. The facades of the Tower are marked by the presence of structural elements coated with thick and dense layers of render and mortar. In-situ and laboratory analyses showed that the high thickness and compactness of the coating played a positive role in preventing the propagation of carbonation and of corrosion. It was estimated that after 50 years most rebars embedded in concrete were either still passive or free from actively-propagating corrosion. Hence it was concluded that most of the original concrete and coating could be preserved without further protection. However, this repair strategy could be compromised by the risk of loss of adhesion of the coating to the underlying concrete, and this crucial aspect should be better investigated in the design of the repair work.