Experimental Study on Crack Width of HRB600 Grade High-Strength Steel Bar Reinforced Concrete Beams

High-strength reinforcement is an important direction in the development of civil engineering. In order to fill the gap that the current concrete structure code GB50010 has no standard regulations applicable to HRB600-grade high-strength reinforcement, this paper conducted an experimental investigation on the crack width of eight concrete beams reinforced with HRB600-grade high-strength reinforcement. The study examined various parameters to understand the crack development process, crack spacing, and factors influencing crack width in the pure bending section. The results revealed that the damage mode and crack development process of high-strength reinforced concrete beams were similar to those observed in ordinary reinforced concrete bending members. The crack spacing in the pure bending section was independent of the concrete strength, and the average crack width in the pure bending section exhibited a proportional relationship with the reinforcement strain. Moreover, both were mathematically related to the ratio of reinforcement diameter and ratio. A calculation formula for the maximum crack width suitable for HRB600-grade reinforced concrete beams was developed and fit. The HRB600-grade high-strength reinforcement had an obvious yield stage and good ductility, and the test study provides a powerful reference for promoting the application of high-strength reinforcement in concrete structures.