Preservation of Historical Ferrocement: An Experimental Evaluation of Corrosion Protection Treatments

The restoration of modern architecture is still a complex issue today, requiring study and innovative techniques to preserve its materials. In this context, ferrocement, a composite material whose fame is due to Eng. Pier Luigi Nervi fits in. Through this thesis, a theoretical and practical analysis was conducted to define the most effective treatments to prevent corrosion in this material. After a general introduction, the history and characteristics of ferrocement are analyzed: patents, applications, and technical and aesthetic advantages. The discussion includes an analysis of the applications of this material around the world, but the focus is on Pier Luigi Nervi's works, particularly the case study of the Palazzo delle Esposizioni in Turin, specifically Pavilions B and C. In the second part, issues regarding the durability of ferrocement are analyzed, analyzing its main degradation factors, such as carbonation and chloride penetration. The main protection techniques, both traditional and new generation, are also presented. The experimental part follows the theoretical analysis of the topic: specially created and treated specimens were subjected to accelerated aging processes. This part is divided into several sections, representing the different stages of the specimens' life cycle: from the fabrication and application of treatments to aging to final mechanical testing. Techniques used to understand the progress of aging include photographic documentation, corrosion potential measurements, porosity analysis with contact sponge, georadar, and the use of iCOR to measure resistivity and corrosion rate. Part of the discussion also analyzes the potential and limitations of re-alkalizing, an electrochemical treatment applied to three specimens. The final part is devoted to the results obtained and related comments, with a comparison of numerical data and an evaluation of the effectiveness of the applied treatments. Re-alkalinization is discussed separately, evaluating not only its results but also its feasibility and practicality in situ versus in the laboratory.