Mechanical properties of the rust layer induced by impressed current method in reinforced mortar

Sabine Caré (1) , Quang Thanh Nguyen (2) , Valérie L'Hostis (3) , Yves Berthaud (2)

1 navier umr 8205 - Laboratoire Navier
2 LMT - Laboratoire de Mécanique et Technologie
3 LECBA - Laboratoire d'Etude du Comportement des Bétons et des Argiles

This paper describes the mechanical effects of rust layer formed in reinforced mortar through accelerated tests of corrosion. The morphological and physico-chemical properties (composition, structures) of the corrosion system were characterized at different stages by using optical microscope and scanning electron microscope coupled with energy dispersive spectroscopy. The corrosion pattern was mainly characterized by a rust layer confined at the interface between the steel and the mortar. Expansion coefficient of rust products was determined from the rust thickness and the Faraday's law. Furthermore, in order to understand the mechanical effects of corrosion on the damage of mortar, displacement field measurements were obtained by using digital image correlation. An analytical model (hollow cylinder subjected to inner and outer pressures) was used with a set of experimental data to deduce the time of cracking and the order of magnitude of the mechanical properties of the rust layer.

Mots clés: SEM; Corrosion; Mechanical Properties; Steel Reinforced Mortar; Rust

Domaines: Mécanique des matériaux [physics.class-ph]; Mécanique des matériaux [physics.class-ph]

Sabine Caré, Quang Thanh Nguyen, Valérie L'Hostis, Yves Berthaud. Mechanical properties of the rust layer induced by impressed current method in reinforced mortar. Cement and Concrete Research, 2008, 38, pp.1079-1091. ⟨10.1016/j.cemconres.2008.03.016⟩. ⟨hal-00363064⟩