Conservation Strategies for the Palazzo degli Affari in Florence (Italy): The Role of Protective Treatments on the Concrete Carbonation Resistance

Water repellent treatments and combined products such as consolidant and hydrophobic formulations have been considered suitable methods to improve durability-related properties of exposed concrete surfaces. Since buildings in urban context usually suffer decay due to carbonation-induced reinforcement corrosion, in this work the authors studied how this range of protective products can affect the carbonation process of the concrete with regard of the case study of Palazzo degli Affari in Florence. An accelerated ageing test by CO2 exposure was performed on concrete mock-ups realised with the same recipe of the original, in order to evaluate the laboratory performance provided by the considered treatments. The assessment of the carbonation resistance was made by analysing the performance of the product actually employed in the conservation intervention of the Palazzo and other commercial formulations. Finally, the experimental results returned by the untreated samples were used to validate the fully-probabilistic method proposed by the fib-Bulletin 34 to predict the development of carbonation depth.