• Ferreira, Rui Miguel
• Puttonen, Jari
• Sistonen, Esko
• Vesikari, Erkki
• Piironen, Jukka
• Al-Neshawy, Fahim

Abstract

This research was done as a part of the project AgingManagement of Concrete Structures in Nuclear Power Plants(MANAGE) in The Finnish Research Programme on NuclearPower Plant Safety 2011-2014, SAFIR 2014. The aim of thisresearch was to carry out condition assessments andcorrosion measurements to evaluate the condition of thereinforced concrete structures of the cooling waterchambers in a Finnish nuclear power plant and to verifythe possible state of corrosion of the reinforcement. Thecondition assessment was based on concrete samples takenfrom the structures above the water level, at the rangeof the water level, and under the water level. Theconcrete samples were subjected to the followinganalyses: the carbonation depth, the chloride profile,and the study of the microstructure based on thinsections. Concrete cover measurements and visualinspection of the concrete structures and exposedreinforcements were done to approve the corrosionmeasurements. These determinations and measured Half-Cellpotentials were used with the Pourbaix-diagrams for steelto estimate the state of corrosion of reinforcement. Themeasured depths of concrete cover correlated the designvalue 60 mm. The average depth of carbonation of concretewas very small; varying between 0 mm and 12 mm.Estimations for the state of corrosion of reinforcementaccording to the Pourbaix-diagrams showed thereinforcement to be in passive state. Visual inspectionsconfirmed the estimation; all of the exposed reinforcingbars were intact.

Topics

• microstructure
• corrosion