Influence of the flexural and shear reinforcement in the concrete cone resistance of headed bars

• Published in: Engineering structures 2021-12, Vol.248, p.113212, Article 113212
• Main Authors: Ferreira, Mauricio, Filho, Manoel Pereira, Lima, Nataniel, Oliveira, Marcos
• Format: Article
• Language: English
• Subjects: Cast-in anchors; Concrete; Concrete cone failure; Concrete cracking; Headed bars; Reinforced concrete; Reinforcement; Stirrups; Supplementary reinforcement; Tensile tests
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2021.113212

•16 pull out tests on headed bars used as cast-in anchors embedded in reinforced concrete members.•Comparison of the results of the 16 experimental tests with available data from literature.•Contribution given by flexural and shear rebars on the concrete cone resistance of headed bars.•Increments of flexural reinforcement ratio can progressively increase the concrete cone resistance.•Shear reinforcement was able to improve the concrete cone resistance of headed bars.•The design codes and theoretical methods underestimated the strength of the tested specimens. This paper presents the experimental response and resistance of sixteen axial tensile tests on headed deformed bars embedded in reinforced concrete members, used as cast-in anchors, under concrete cone failure. Nine of these tests investigated the influence of the flexural reinforcement ratio, which affects the concrete cracking state in the vicinity of the anchor. The other seven tests measured the shear reinforcement contribution, adjusted to work as supplementary reinforcement, distributed in the tests in different amounts and arrangements. Furthermore, design and theoretical methods were used to discuss the authors' experimental results compared to other literature results. The flexural reinforcement ratio significantly influenced the concrete cone resistance, as it controls the crack width. Well-detailed stirrups, placed following the design codes' spacing limitations for supplementary reinforcement, can substantially increase the concrete cone resistance. The assumptions underlying the design methods are conservative, which is justified by the simplicity of their equations, but more accurate calculation methods are required.