Numerical assessment of bond-slip relationships for naturally corroded plain reinforcement bars in concrete beams. (15th July 2021)

• Record Type: Journal Article
• Authors: Yu, Xiaotong; Robuschi, Samanta; Fernandez, Ignasi; Lundgren, Karin
• Is Part Of: Engineering structures. Volume 239(2021)
• Publication Date: 2021-07-15
• Subjects: Corrosion -- Plain reinforcing bars -- Bond -- FE analyses -- Reinforced concrete; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2021.112309
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: 1D bond-slip relations of naturally corroded plain bars in RC beams were calibrated. Asymmetry in the yield penetration and bond loss at yielding were crucial factors. Bars were divided in yielded and unyielded zones with different bond-slip relations. Spalling reduced residual bond stress, splitting cracks had no significant effect. Load-deflection curve, crack pattern and asymmetry agreed with the test results. Abstract: Reinforced Concrete (RC) heritage structures are often affected by corrosion. Consequently, knowledge about the effect of corrosion on the bond between reinforcing bars and surrounding concrete is critical when assessing the structural performance of these structures. In earlier work, structural tests were carried out on segments of edge beams taken from a decommissioned RC bridge. The specimens had naturally corroded plain reinforcement bars and three-point bending tests were conducted, to investigate their anchorage capacity. In this study, non-linear finite element analyses (NLFEA) were carried out to gain further insight into the bond behaviour of the tested specimens, including the effect of corrosion on the bond-slip relationship. Two different, one-dimensional (1D), bond-slip relationships were calibrated for each tested bar, to account for loss of bond upon yielding. The calibration process was based on a comparison between significant numerical and experimental results, including load–deflection curve, crack pattern and asymmetrical distribution of the yield penetration along the length of the bar. Good agreement between the FE analyses and experimental tests was observed. Finally, the calibrated bond-slip relationships for nine beams with different corrosion levels, casting positions, and visual damage are presented and discussed. The loss of bond at yielding and yield penetration asymmetry are both shown to be crucial factors for adequately describing structural behaviour.