Method for monitoring the state of corrosion of metallic pillars and posts, embedded in concrete foundations

摘要

Method for electrochemical monitoring of metallic pillars and posts embedded in cement foundations and for ascertaining and analysing the state of corrosion of the portion of the posts, which is embedded in the foundation, characterised by the monitoring of all the structures of which the system is composed, the principle of linear polarisation being employed, in which a reference electrode and a counter electrode are used and measured values are registered by an instrument which is connected to the metallic structure and the two electrodes. This measuring instrument registers the free corrosion potential and the potential changes in the metallic structure at various, predetermined strengths of the polarisation current induced to this end, whereupon the polarisation resistance is determined from the ratio between the potential change and the polarisation current at various current strengths, after which the size of the corrosion current and thus of the corrosion rate is determined, whereupon, finally, the data thus determined are compared with the data of all the structures of the system and those structures are found in which the corrosion rate is highest, so that any destructive intervention for more detailed examination and possible repair or replacement is restricted to said few structures. IMAGE