Microscopy study of the interface between concrete and conductive coating used as concrete CP anode
conference paper
Samples were studied of conductive coatings that had served as anode material in concrete cathodic protection (CP) systems in Norway and The Netherlands for up to about 9 years, using light microscopy of thin sections of about 25 pm thickness and scanning electron microscopy (SEM).
Observation of the coating/concrete interface revealed that the depth of dissolution due to acid formation in the interface was less than 10 pm according to light microscopy and less than 1 pm by SEM. This suggests that the service life of a CP system based on the investigated conductive coating is not limited by acid production caused by current flow. Looking at the good interfacial properties of the 9 year old samples, the service life expectation is well over 10 years. Loss of bond due to mechanical or thermo-mechanical factors may be more critical than chemical effects associated with the flow of protection current.
Observation of the coating/concrete interface revealed that the depth of dissolution due to acid formation in the interface was less than 10 pm according to light microscopy and less than 1 pm by SEM. This suggests that the service life of a CP system based on the investigated conductive coating is not limited by acid production caused by current flow. Looking at the good interfacial properties of the 9 year old samples, the service life expectation is well over 10 years. Loss of bond due to mechanical or thermo-mechanical factors may be more critical than chemical effects associated with the flow of protection current.
TNO Identifier
979459
Source
Paper presented at Eurocorr'01, Riva del Garda, Italy
Collation
3 p.
Files
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