Evaluation of fly ash effect on the durability of prestressed concrete cylindrical pipe in aggressive soil by electrochemical method

• Published in: Chemical Data Collections 2021-04, Vol.32, p.100656, Article 100656
• Main Authors: Berrami, K., Ech-chebab, A., Galai, M., Ejbouh, A., Hassi, S., Benqlilou, H., Ouaki, B., Ebn Touhami, M.
• Format: Article
• Language: English
• Subjects: Chloride and sulfates ions; Concrete; Corrosion; EIS LPR; Fly ash; OCP; PCCP; Soil
• ISSN: 2405-8300; 2405-8300
• DOI: 10.1016/j.cdc.2021.100656

This research paper discusses an experimental study aimed at enhancing the durability of mortar coating on pre-stressed concrete cylindrical pipes (PCCP) exposed to corrosive soil. Two mortar coating mixtures were studied: a control mixture before and after adding 17% fly ash. The specimens were exposed to Kenitra soil (non-aggressive soil) and Errachidia soil (the most aggressive environment). Several electrochemical techniques have been used such as open circuit potential (OCP), the linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) to assess the corrosion of steel wire coated with thick mortar coatings mixture under accelerated corrosion by an impressed constant voltage. The visual examination, Scanning Electron Microscopy (SEM) coupled with EDS analysis, Chloride penetration depth, and carbonation depth were performed to confirm experimental results. The results indicated that the fly ash blending in mortar coatings of prestressed concrete cylinder pipe (PCCP) improves the corrosion resistance of the prestressed wires in despite the strong and prolonged attack by aggressive soil.