DEVELOPMENTS IN GALVANIC ANODE TECHNOLOGY FOR REINFORCED CONCRETE REPAIRS,INCLUDING THE LATEST TECHNOLOGICAL INNOVATIONS

摘要

Discrete,sacrificial galvanic anodes have been accepted and used globally for over twelve years,to assist with long term durability of reinforced concrete patch repairs and in particular to minimize the impact of the”incipient anode”effect.Each generation of anode has introduced to the market numerous innovations,including those regarding constituent materials and fundamental design principals.Progressive design improvements are aimed at achieving longer design life and durability,greater protection to the steel reinforcement and an easier,more economical application.Corrosion researchers are now pushing the boundaries in terms of material selection and industrial design to maximize their benefit,with extensive laboratory research modelling,then helping demonstrate,superior anode performance in the field.The latest engineered versions of discrete galvanic anodes include a”chemical hybrid”which is used to”jump start”the galvanic action,without the cost and inconvenience of having to connect additional electrical driving currents to the system.Clever detailing of size and shape enables improved application of encasement mortar and improved charge distribution.This paper reviews the development history and performance of discrete galvanic anodes,including a discussion on fundamental design features of shape and form,materials,encasement mortars and installation issues.It further includes an insight into the latest advanced technology in discrete galvanic anodes available to asset owners,contractors and specifiers,thereby allowing the best selection possible of anodes,in the ongoing desire to build-in readily available,low cost,longer service life repairs,to reinforced concrete structures.