The effect of temperature and concentration of sulfuric acid on the concrete crown corrosion

It`s impossible to overhaul the sewer collection lines, or remove sewer lines from the sewage system. As a result, the necessary studies should be performed to identify appropriate strategies to prevent blockage of the pipes. One of the common problems in the field is crown corrosion due to the presence of sulfuric acid. In this study, the production of sulfuric acid in the presence of microbiological agents in pipes’ crown has been studied and the effect of environmental parameters such as temperature and acid concentration on the rate of the biological crown corrosion were investigated. For this purpose, concrete samples of the type 5 of cement used in accordance with the ASTM C150 and ASTM C595 standards, and then they were exposed to the different temperatures and concentrations of sulfuric acid. The results of the weight loss indicate that the increases in the temperatures and concentrations of acid would be led to higher corrosion rates. Finally, optical microscopic investigations and XRD analysis of the corroded sample showed that the corrosion product is ettringite.