Prediction of the residual load-bearing capacity of naturally corroded beams using the variability of tension behaviour of corroded steel bars

Abstract

This paper shows the residual behaviour of a highly corroded beam stored under sustained load in a chloride environment for 28 years. A non-corroded beam of the same age was also kept under sustained loading but in a non-aggressive environment as a control beam. Both beams were subjected to a three-point bending experiment until failure. The lower tensile reinforcement was extracted so that the tension properties of the corroded bars could be investigated. The yield strength, ultimate strength and ultimate strain of the corroded bars followed a normal distribution. Both the average value and the characteristic value of the yield strength, ultimate strength and ultimate strain were used to predict the residual mechanical performance of the beams. The changes in yield capacity and ultimate capacity of the corroded beam in comparison with the non-corroded beam are discussed in relation to the damage to the steel reinforcing bars. According to the variability of the residual behaviour of steel bars in tension experiment, it is possible to predict the variability in the load-bearing capacity of the corroded beams which fail due to the rupture of the tension bars.

Investigating correlations between crack width, corrosion level and anchorage capacity

“…Therefore, corrosion may to a great extent decrease the service life of RC structures. Many research studies have been focusing on the relationship between the degree of corrosion of steel reinforcement bars and the load-carrying capacity of corresponding RC elements (Azad et al, 2007;Cairns & Millard, 1999;Dang & François, 2014;Law, Du, Cairns, 2008;Saether, 2011;Zhu & François, 2016); Fernandez, Herrador, Marí, & Bairán, 2016), and several empirical, analytical and numerical models relating corrosion level to load-carrying capacity have been developed (Wang & Liu, 2004;Berra, Castellani, Coronelli, Zanni & Zhang, 2003;Lee, Noguchi & Tomosawa, 2002;Bhargava, Ghosh, Mori & Ramanujam, 2008;Lundgren, 2005;Biondini & Vergani, 2014). However, since corrosion levels cannot be easily measured in existing structures, these models do not yet have any direct practical application.…”

Effect of different material constitutive models in estimating the residual moment capacity of RC beams subjected to natural corrosion

“…, 2009; Zhu et al. , 2013, 2015; Zhu and François, 2016). The beams have undergone a series of continuous spraying and wetting-drying cycles for 3–27 years before subjecting them to a three-point loading system.…”

“…The data from Laboratoire des Mat eriaux et Durabilit e des Constructions (LMDC) were obtained from a long-term experimental program that started in 1984 in Toulouse, France. The 19 RC beams were taken from 13 different collaborative groups who were involved in the project (Castel et al, 2000;Dang et al, 2016;Dang and François, 2014;François et al, 2013;Khan et al, 2012Khan et al, , 2014Kreit et al, 2011;Vidal et al, 2007;Yu et al, 2015;Zhang et al, 2009;Zhu et al, 2013Zhu et al, , 2015Zhu and François, 2016). The beams have undergone a series of continuous spraying and wetting-drying cycles for 3-27 years before subjecting them to a three-point loading system.…”

Corrosion Effect on Bond Loss between Steel and Concrete

“…Nonetheless, experimental results of both bare and embedded corroded steel reinforcement mainly showed ductility drop rather than reduction of effective stress. To this effect, several studies targeted on the relationship between the degree of corrosion of steel reinforcement and the bearing capacity of corresponding reinforced concrete structures [17][18][19]. Recently, Kashani et al [20] presented a state of the art review up to date concerning the current knowledge upon residual capacity of corroded RC elements.…”