Corrosion of reinforcing steel and low cycle fatigue behaviour

• Published in: Materials and corrosion Vol. 58; no. 6; pp. 438 - 446
• Main Authors: Apostolopoulos, Ch. Alk, Michalopoulos, D.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01-06-2007; WILEY‐VCH Verlag; Wiley-VCH
• Subjects: Applied sciences; BSt500s steel; Chloride corrosion; Corrosion; Corrosion environments; Exact sciences and technology; Fatigue; low cycle fatigue; Mass loss; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; plastic deformation; reinforcing steel; Concrete reinforcing bar; Mechanical properties; Corrosion; Application; Low cycle fatigue; Reinforced concrete
• ISSN: 0947-5117; 1521-4176
• DOI: 10.1002/maco.200604026

Chloride induced corrosion of reinforcing steel can be highly detrimental and of great influence on the low cycle fatigue (LCF) characteristics. An experimental study conducted on BSt500s reinforcing steel, showed that the LCF and life expectancy were reduced considerably according to the level of corrosion. Low cycle strain controlled fatigue testing under ± 1 and ± 2.5% constant amplitude strain indicated that the corroded steel bars exhibit gradual reduction in available energy, number of cycles to failure and the load bearing ability. Formation of irregularities such as pits, notches and cavities occurred on the corroded steel surface and stress concentration points were developed which are highly localized at imperfections and especially at the rib bases. The experimental investigation of the corroded specimens subjected to LCF showed that the life expectancy, the remaining energy density and the strength properties were reduced considerably as a result of these irregularities combined with the mass loss and reduction of the exterior hard layer of martensite. Structural design capable of resisting seismic activity that does not account for the reduction of the load bearing ability and life expectancy as well as the cumulative plastic deformation of the steel reinforcement due to corrosion and loading history that a structure will be subjected in harsh climatic environments and ground oscillating motion could lead to serious and unpredictable performance.