دانلود رایگان مقاله ارزیابی خوردگی عناصر بتن مستحکم توره ولاسکا در میلان

ABSTRACT

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.

7. Conclusions

Based on the results of the inspection, the following conclusions can be drawn. 1. A significant effect of local exposure conditions, i.e. height and orientation, on carbonation depth did not emerge. 2. The presence of coating with high thickness, cementitious nature and low porosity both prevented concrete carbonation and delayed the ingress of water into concrete. Hence, most rebars embedded in concrete were either still passive or free from actively-propagating corrosion. 3. A repair strategy based only on the repair of the few local cracked areas is proposed, whilst the sound concrete, even if carbonated, should not be removed. 4. However during the design of the repair works the possible detachment of the coating from the underlying concrete should be assessed and in case the detachment involved large areas the replacement of the original coating with a new cement layer is advisable.