Author(s)

P. Lambert & A. R. Foster

Abstract

The maintenance and remediation of historic structures naturally lends itself to the use of traditional materials and methods. While ‘like for like’ remains the gold standard, there are situations that may mean alternative materials and methods need to be considered. Many of these approaches are associated with the prevention or control of corrosion of metallic components used as reinforcement, fixings or decoration. Common alloys of iron and carbon, such as steel, cast iron and wrought iron, are totally synthetic, essential unstable and prone to corrosion. A number of electrochemical approaches are available to extend the life of metallic items. Corrosion can also be controlled by chemical methods in the form of inhibitors. Red lead provided this form of protection but newer organic options have become available that can be used with or without a coating system. In addition to concerns over the durability of structures, there can often be problems with their structural capacity. Fibre reinforced composites (FRC) in resin matrixes originally developed for reinforced concrete can also be applied to stone and brick masonry, timber and cast iron. The polymer component in FRC can result in creep, poor fire performance and attack by UV, solvents and heat. Replacement of the organic matrix with an inorganic matrix could resolve such limitations and recent developments, such as geopolymers, essentially artificial rock, may be one such answer. Finally, the rapid development in sensor and remote interrogation technology allows sensitive structures and their enhancements to be effectively monitored without detracting from the historic and aesthetic values. Keywords: cathodic protection, electrochemical chloride extraction, realkalisation, corrosion inhibitors, fibre reinforced composites.

Keywords

cathodic protection, electrochemical chloride extraction, realkalisation, corrosion inhibitors, fibre reinforced composites