Inelastic cyclic behaviour of asreceived and precorroded S500s tempcore steel reinforcement

• Published in: International journal of structural integrity Vol. 1; no. 1; pp. 52 - 62
• Main Authors: Apostolopoulos, Ch. Alk, Rodopoulos, C.A.
• Format: Journal Article
• Language: English
• Published: Emerald Group Publishing Limited 05-03-2010
• Subjects: Mechanical behaviour of materials; Reinforcement; Steel; Stress materials; Viscosity
• ISSN: 1757-9864
• DOI: 10.1108/17579861011023793

Purpose Seismic loading can induce significant deformations to steel reinforcement. The recent approach suggested by Eurocode 8 indicates that steel reinforcement shall sustain repeated loading well within its elastic region, excluding by definition seismic loading. This paper aims to examine the behaviour of S500s steel reinforcement at strain ranges representing strains corresponding to smallmedium earthquakes while significant attention has been paid to cases where the reinforcement has been corroded as this is most representative to aged buildings. The work concludes that the complex behaviour of steel reinforcement under low cycle fatigue conditions can be successfully treated via the use of the viscous stress. The latter is found to be independent to corrosion exposure while it holds the merits of ductility exhaustion on which most degradation models are based. Designmethodologyapproach This paper establishes a relationship between the cumulative effect of low cycle fatigue and that of the viscous stress. Findings The work identifies that the viscous stress follows an exponential growth behaviour which terminates at a plateau. The plateau value is found to be independent to corrosion exposure and strain rate and hence providing a strong potential for being a characteristic indicator of the behaviour of steel reinforcement under realistic inelastic loading. Research limitationsimplications The study is limited to S500s grade steel. Further study on different steel grades is necessary to increase the potential of viscous stress. Originalityvalue The significance of this paper is the introduction of viscous stress in an area where traditional approaches of cumulative damage are based on a large number of empirical parameters and assumptions.