Investigation on the use of iron and steel for restoration purposes during 19th and 20th century
Tutor / directorRoca Fabregat, Pedro
Document typeMaster thesis
Rights accessOpen Access
Since the earliest times, wrought iron cramps and dowels were used in the traditional masonry structures to secure stones which might be prone to movement or displacement. In the period between the late 19th century and the early 20th century, masonry-clad buildings are exploded to use. However, due to the porous nature of the mortar and the inconsistent fill around the steel members, the protective oxide film is lost over time, resulting in corrosion of the steel framing and other embedded metals. The metals which are used for historical construction are cast iron, steel and wrought iron. The causes of metal deterioration are corrosion, mechanical breakdown, weathering and connection failure. The traditional restorations are repair, replacement and jointing method. And new, a new method, cathodic protection, is also applied on historical building restoration. New materials began to be used for replacing the original materials, The most common have been aluminum, epoxies, reinforced polyester, glass fiber-reinforced concrete and titanium. The first cathodic protection system for stone clad steel framing was installed in 1991. Cathodic protection (CP) prevents corrosion by converting all of the anodic sites on the metal surface to cathodic sites by supplying electrical current from an alternate source. Different from the traditional way, CP method does not to remove the masonry and install new masonry back. According to Roberto Pane, the extreme variety of cases and the need for safeguarding a large amount of monuments shows that restoration can not be constrained within stiff limits .As a conclusion of this studying, due to the former experience, the Barcelona Cathedral’s façade can be considered to use the CP method for restoration blend with the old with regard to size, scale and appearance.