Investigation on the use of iron and steel for restoration purposes during 19th and 20th century

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hdl:2099.1/7897
Document typeMaster thesis
Date2008-07
Rights accessOpen Access
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Attribution-NonCommercial-NoDerivs 3.0 Spain
Description
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.