Corrosion processes and ECE treatment in a both carbonated and chlorinated reinforced concrete

Author(s): Yolaine Tissier, Véronique Bouteiller, Elisabeth Marie Victoire, Suzanne Joiret, Thierry Chaussadent
Paper category: Proceedings
Book title: Proceedings of the International RILEM Conference on Materials, Systems and Structures in Civil Engineering Conference segment on Electrochemistry in Civil Engineering
Editor(s): Lisbeth M. Ottosen
ISBN: 978-2-35158-176-6
e-ISBN: 978-2-35158-177-3
Publisher: RILEM Publications SARL
Publication year: 2016
Pages: 130-140
Total Pages: 11
Language : English

Abstract: Civil engineering structures and historical buildings can suffer from corrosion of the embedded reinforcing steel once the concrete cover is totally carbonated and/or when chloride ions reached the steel/concrete interface. On field, these two types of contamination can be encountered separately or combined requiring implementation of proper repair methods. In this study, both chlorinated and carbonated reinforced concrete specimens were followed by three main analysis means: Raman microspectroscopy, electrochemical characterization and scanning electron microscopy. They were first characterized during the two-step aging process, chlorides addition and complete cover carbonation. Electrochemical chloride extraction was then performed as a repair treatment (1A/m² of steel surface during 8 weeks). Its efficiency and its impact on the specimen interface and cement matrix were studied. Study of rebar’s electrochemical characteristics during the aging notably showed an increase of corrosion rate from negligible value of 0.1 μA/cm² after fabrication to above 10 μA/cm² after carbonation. SEM observations confirmed this phenomenon with the identification of a corrosion layer on most of the concrete/steel interface after carbonation. The ECE efficiency was put in evidence by a decrease of Cl- concentration below the theoretical threshold value of 0.4 % mass of cement after two weeks. Simultaneously a realcalinisation was observed around the reinforcement bar which reached about 1 cm in 28 days.

Online publication : 2016
Publication type : full_text
Public price (Euros) : 0.00