Boundary element modeling of cathodic protection systems for steel framed masonry buildings

There has been an increasing awareness over the last 30 years that many high-profile steel-framed masonry buildings are susceptible to extensive damage as a result of corrosion of the steel frame. This form of construction initially was employed in Chicago and New York and was subsequently used in most US and European cities in the first two decades of the 20^th century, and has resulted in potentially serious consequences with respect to serviceability, safety, aesthetics and heritage.

Cathodic protection (CP) 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 employed to model 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.