Bond of steel bars embedded in plain and fiber-reinforced concrete of different strengths

Abstract This paper presents the results of an experimental investigation into the bond characteristics between steel reinforcement and both plain and fiber-reinforced concrete. The study analyzed steel bars with diameters of 10 mm and 16 mm, embedded in concrete specimens with compressive strengths of 30 MPa, 60 MPa, and 90 MPa. Steel fibers, measuring 13 mm and 25 mm in length, were incorporated into the concrete at volumetric fractions of 1% and 1.5%. Additionally, a combination of both fiber types, totaling 1% in volume, was evaluated. A comparison with analytical models for bond strength determination was conducted. The results indicate that the inclusion of steel fibers did not significantly impact bond strength, and all standard codes exhibited a conservative trend compared to the findings of this study.