Investigation of the effects of multiple and multi-directional reinforcement on corrosion-induced concrete cracking pattern

• Published in: Construction & building materials 2021-05, Vol.283, p.122594, Article 122594
• Main Authors: Zahid, Hafiza Fatima, Jiradilok, Punyawut, Singh Kuntal, Vikas, Nagai, Kohei
• Format: Article
• Language: English
• Subjects: Confinement; Corrosion crack; Cover depth; Multiple rebars; Rebar orientation
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2021.122594

•The effects of multiple and multi-directional reinforcement on corrosion-induced cracking pattern.•The effect of corrosion location and the change in order of corrosion occurrence on the crack pattern.•Orthogonal crack patterns emerged even when bars of only one direction corrode.•The absence of visible longitudinal surface crack due to continual pressure from multiple corroding rebars. Reinforced concrete (RC) structures are widely used, yet prone to damage induced by reinforcement corrosion which causes susceptibility of concrete spalling and eventually a reduced serviceable life. The visual inspection has been performed usually for structural assessment, but this does not account for the local interactions between rebars. Consequently, detailed scrutiny is required to consider the effects of various parameters on the initiation and propagation of corrosion-induced cracking. This experimental study considers the effect of multiple and multidirectional rebars on the development of corrosion cracking. Additionally, the effect of the location of corrosion and the change in order of corrosion occurrence is investigated in this research. For this purpose, reinforced concrete panels with unidirectional and multidirectional rebar arrangements and varying cover depth are tested using an accelerated corrosion technique. The results show a significant role of confinement in controlling the widths of cracks provided by both reinforcement arrangements. Moreover, the effect of boundary conditions along with increased confining pressure alters the generation of cracks in a unidirectional reinforcement arrangement. In the absence of enough surrounding concrete, cracks along non-corroding rebars can also form because of the expansion of adjacent corroding rebars. The inclusion of multidirectional reinforcement alters the crack direction and causes cracking along non-corroding rebars. Further, previously generated cracks may close considerably by the pressure from adjacent rebar corrosion. This study also facilitates the comprehension of the impact of influencing factors affecting corrosion cracking in real structures.