The bond strength between steel reinforcement and concrete is one of the most important physical properties that determine the performance of reinforced concrete. This research aims to study the bond behavior between reinforcing bars and recycled aggregate concrete reinforced with basalt fibers and containing recycled concrete aggregate. An experimental study was conducted on fifteen samples using a push-out test to investigate the bond strength for several variables. Seven variables were studied in this study: the natural aggregate replacement ratio, compressive strength of the concrete, basalt fibers content, thickness of concrete cover, embedded length of bar, diameter of the reinforcing steel, and the yield strength of reinforcement. The results showed a 20% decrease in bond strength at 100% aggregate replacement compared with conventional concrete. Bond strength improved with increasing compressive strength and thickness of concrete cover by 35% and 49%, respectively, when compressive strength increased from 25 to 45 MPa and concrete cover from 67 to 117 mm. Bonding behavior also improved significantly when the yield stress was increased from 420 to 650 MPa, with an improvement ratio of 32%. Regarding the bar diameter and embedded length, it was observed that increasing the diameter from 16 to 25 mm and increasing the embedded length from 7d to 12db mm resulted in a clear decrease in bonding strength, reaching 36% and 40% respectively. Adding basalt fibers in low percentage content, not exceeding 1%, does not significantly affect bond strength or failure mode. However, increasing the fiber content to 1.5% increased bond strength by approximately 15% compared to 1%.
