Corrosion induced cover cracking studied by X-ray computed tomography, nanoindentation, and energy dispersive X-ray spectrometry (EDS)

• Published in: Materials and structures 2015-07, Vol.48 (7), p.2043-2062
• Main Authors: Šavija, Branko, Luković, Mladena, Hosseini, Seyed Amir Sajjad, Pacheco, José, Schlangen, Erik
• Format: Article
• Language: English
• Subjects: Building Materials; Cements; Civil Engineering; Corrosion; Corrosion tests; Engineering; Machines; Manufacturing; Materials Science; Mathematical models; Nanoindentation; Original Article; Processes; Rusting; Solid Mechanics; Stress corrosion cracking; Theoretical and Applied Mechanics; X-rays
• ISSN: 1359-5997; 1871-6873
• DOI: 10.1617/s11527-014-0292-9

In this study, several experimental techniques are utilized to study different aspects of cracking of the protective cover due to reinforcing steel corrosion. Firstly, micro-computed X-ray tomography technique (CT-scanning) is used for monitoring rust formation during accelerated corrosion of reinforcement, and subsequent cover cracking. Secondly, the nanoindentation technique is employed to determine mechanical properties of the rust layer, which is an important input parameter for numerical models. Finally, energy dispersive X-ray spectrometry is used for elemental mapping around the steel–cement paste interface. Also, as a part of the study, the resistance of a strain hardening cementitious composite (SHCC) to corrosion induced cover cracking is examined. It was found that CT-scanning can be successfully utilized in non-destructive monitoring of the corrosion process in reinforced specimens. The nanoindentation study showed that the Young modulus of rust is highly dependent on the level of confinement provided to the rust layer by the surrounding cement paste. And, finally, SHCC proved to be an excellent alternative to brittle cementitious materials when corrosion induced cracking of the cover is a concern.