Correlative Raman-SEM-EDX analysis of corroded components In particularmicrobiologically induced corrosion (MIC) of steel, chlorid corrosion (CIC) ofconcrete and alkali–silica reaction (ASR)

Direct costs due to corrosion worldwide amount 3% - 5% of the GDP (gross domestic product) [1][2].Secondary cost like production losses or efficiency loss can be much higher [3]. Apart from these enormouscosts and the economic consequences, in many areas, corrosion represents a very high safety risk (e.g.aircraft and pipelines). MIC is responsible for 20% of all corrosion damage [4]. In this context, there is greatinterest in understanding MIC especially, since it has been shown that some microbes slow down the rate ofcorrosion [5], while others speed it up [6]. The fact that the composition of bacterial cultures and biofilms canvary greatly [7], makes any newly discovered composition an interesting topic to study. CIC occurs whenchloride ions penetrate steel surfaces in concrete, causing rust formation and structural damage. ASR, areaction between alkalis in cement and silicates in aggregate materials, can cause expansive cracking anddamage in concrete structures.