There has been an increasing awareness over the last 30 years that many
high-profile steel framed masonry buildings can be susceptible to extensive
damage as a result of corrosion of the steel frame. This form of construction
was initially employed in Chicago and New York and was subsequently used in
most US and European cities in the first two decades of the 20th century,
leading to potentially serious consequences with respect to serviceability,
safety, aesthetics and heritage.
Cathodic protection is a proven method for preventing and protecting
buried and submerged steel and reinforced concrete structures from corrosion.
More recently, the method has been further developed so as to allow the
treatment of steel framed masonry structures. However, one of the major
problems in understanding the mechanisms of cathodic protection in steel
framed construction is the relatively complex geometry of the systems under
consideration. No analytical solution exists with respect to current throw onto
typical steel sections, yet this is fundamental to the design of such systems.
In this paper, boundary element methods are discussed with respect to the
modeling of the distribution of current and potential on steel surfaces in
representative cathodic protection systems for steel framed masonry
structures. The influence of masonry type and joint width has also been
studied, along with the risks of stray current corrosion. The results of these
studies assist in the design of optimized cathodic protection systems for such
structures. In addition, the application of the boundary element technique for
the analysis of cathodically protected reinforced concrete structures is also
discussed.
Keywords: Corrosion, Steel Frame, Cathodic Protection, Impressed Current,
Numerical Modeling