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Electrochemical corrosion tests on steel in alkali-activated materialsNina Gartner,
Miha Hren,
Tadeja Kosec,
Andraž Legat, 2021, published scientific conference contribution
Abstract: One of the potential alternatives to Ordinary Portland Cement (OPC) are Alkali-Activated Materials (AAMs). The service life of reinforced concrete structures greatly depends on the corrosion resistance of embedded steel reinforcement. Due to the wide range of AAMs and their diverse properties, corrosion processes of steel in these materials are relatively unknown. Corrosion monitoring methods or their interpretations in certain cases cannot be directly transferred from the ones for OPC materials. The chemical compositions of pore solution in different AAMs influence the results of electrochemical measurements and their interpretations. Within this research, three different alkali-activated mortar mixes were prepared, based on fly ash, slag or metakaolin. Pore solutions were extracted from each mortar andchemical analysis was acquired. Different electrochemical corrosion measurements were performed on steel submerged to synthetic pore solutions. In parallel, ordinary carbon steel reinforcing bar was installed in the same types of alkali-activated mortar mixes. Specimens were exposed to wet/dry cycles with saline solution and periodic measurements of electrochemical impedance spectroscopy (EIS) were performed. Measured parameters in both systems were analysedand compared. It was concluded that electrochemical measurements in pore solutions can provide basic overview on corrosion behaviour in different AAMs environments. Periodic EIS measurements enabled monitoring of corrosion initiation and propagation on steel reinforcement in AAMs, although the information on the corrosion type is missing. Interpretation of results depends on visual analysis of corrosion damages after the end of exposure, providing information on corrosion type and intensity. The continuation of research on corrosion monitoring techniques will be performed by using Electrical Resistance (ER) sensors and Coupled Multi-Electrode Array (CMEA) sensors.
Keywords: corrosion, alkali-activated mortars, pore solution extraction, electrochemical corrosion techniques, visual analysis
Published in DiRROS: 22.01.2024; Views: 252; Downloads: 126
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