Mathematical law of steel thickness loss versus time applied to reinforced concrete contaminated by chlorides – first results

Author(s): Véronique Bouteiller, Elisabeth Marie-Victoire, Christian Cremona, Nina Coulaty-Chin
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: 36-45
Total Pages: 10
Language : English

Abstract: In civil engineering constructions, one of the major factors responsible for the deterioration of reinforced concrete (RC) structures such as bridges for example is the corrosion of the rebars. In order to evaluate the durability of RC structures, the corrosion in its propagation phase needs to be ascertained.
In this study, chloride contaminated reinforced concretes (chlorides were either added in the mix (G) or have penetrated by wetting/drying cycles (I)) have been exposed to different environmental conditions: outdoor and six controlled conditions based on two temperatures (20°c and 45°C) and three relative humidities (60%, 80% and 92%). Within a five years study, rebar corrosion was evaluated four times a year, using electrochemical measurements (half cell potential, linear polarization resistance, Nyquist impedance) and corrosion rate was calculated. These latter values were converted in steel thickness loss (stl) versus time (t) in order to propose a mathematical law for simulating/predicting corrosion.
A mathematical power law (stl=atα with α>1) experimental points better than a linear law. Moreover, the results obtained at 20°C and 80% RH were very close to those obtained outdoor for I specimens. Finally, crack behaviour depended on the chloride contamination type, the environmental condition and the time.

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