Investigation of corrosive potential of groundwater in Aksaray city center

The majority of research on buildings after major earthquakes reported that corrosion affected building damage. Corrosion observed in buildings is the physicochemical dissolution that occurs in concrete and reinforcement materials in contact with groundwater. Groundwater with a high harmful ion effect corrodes concrete and reinforcement with which it is in contact. The two most important factors that increase the severity of corrosion are the quality of the concrete and the ion content of the groundwater. Determining the corrosion risk at the design and planning stage is very important for the construction industry, because the measures to be taken after the building is completed may cause significant economic losses. In this study, the corrosion potential of Aksaray city center, the spatial distribution of the corrosion risk and the hydrogeochemical properties of groundwater were investigated. To examine the ion contents of groundwater, water chemistry analyzes of water samples collected from 50 different wells were carried out. In the study area, water type is Ca-SO4 for 12%, Mg-SO4 for 4%, Mg-HCO3 for 12%, and Ca-HCO3 for 72% of the water samples. The order of cations and anions for many water samples are Ca+2 > Mg+2 > Na++K+/ HCO3 - > SO4 -2 > Cl- . Corrosion potentials of sampling points were determined by using corrosion indices such as the Langelier saturation, the Agresiflik, Larson-Skold, Puckorius, and the Ryznar index, which are widely used in the literature, and water analysis results. For spatial distribution maps, the corrosion potential is classified into three different groups: highly corrosive water, low corrosive water, and non-corrosive water. According to the results of the Ryznar, the Puckorius, Langelier, Larson-Skold, Agresiflik, 88%, 44%, 66%, 24%, and 0% of the water samples are classified as "highly corrosive water", respectively. The index with the highest percentage of corrosion risk is the Ryznar. The areas with the highest corrosion risk are mostly located in the northwest and southeast parts of the study area. The corrosion potential of the region is mostly increased due to the dissolved carbon dioxide content. There is a positive linear correlation between the corrosion potential and the dissolved carbon dioxide content. Groundwater has dissolved carbon dioxide values ranging from 5.1 mg/L to 482.3 mg/L. The reason for the high carbon dioxide values detected is the magmatic intrusions that settled in the region due to the Hasandağı volcanism. Keywords: Corrosion Risk, Corrosion İndex, Spatial Distribution, İnterpolation, Aksaray