An innovative cathodic protection system for steel framed heritage structures

Abstract

The corrosion of early 20th century steel-framed buildings is resulting in serious damage to the integrity and appearance of many historically important structures. Since the application of cathodic protection to steel framed buildings in the late 1990s it has been proven to provide a low intrusive and aesthetically acceptable technique for the conservation of heritage structures.The principles of cathodic protection have not changed since its discovery by Humphry Davy in 1824 but have been adapted to a wide range of structures over the subsequent 190 years. The systems itself have been refined and improved over time except in the case of steel framed buildings where it is still in its early years. This paper discusses the application of an innovative cathodic protection system on steel framed buildings that utilises a geopolymer with admixed carbon fibres. The system does not require the installation of additional discreet anodes and is in the form of a repointing mortar in the joints of the cladding from where it is able to provide protection. The principles of the system and its first commercial application are presented.

Structural Performance of Concrete Elements Retrofitted by a Geopolymer Strengthening System: Input in the Rehabilitation of Historical Buildings

“…Meanwhile, carbon-based SFRG was used as an innovative cathodic protection (CP) system on historical steel framed buildings. This system was first applied at Leeds Civic Hall, a magnificent steel-framed, Portland stone clad Grade II-listed building that was built in 1933 [29]. The installation, comprising both the conductive geopolymer and a conventional rod anode CP system, was placed at the rear façade.…”

“…Monitoring of the system showed that the geopolymer CP system achieved effective protection to the steel frame as the conventional CP system. Likewise, SFRG CP system was installed at the main entrance in a historic Kansas City building, Missouri, USA that was built in 1906 [29]. Although the facade remained in good condition, by the start of the new millennium it was showing signs of corrosion to the steel frame and cracking of the granite at the grand main entrance.…”