HRB335 is a secondary steel. H stands for hot rolling, R stands for ribbed bar, B stands for bar, and 335 stands for minimum yield point. The first grade steel is HRB235, the second grade steel is HRB335, the third grade steel is HRB400, and the fourth grade steel is HRB500. HRB steel bar, that is, hot rolled ribbed steel bar, refers to the surface deformation of steel bar through hot rolling process to increase the bite force with concrete. Include surface ribbed steel bar, spiral steel bar, herringbone steel bar and crescent steel bar. The role of reinforcement: the buckle reinforcement is the negative reinforcement of the slab, and both ends are buckled on the formwork, commonly known as the buckle reinforcement, which bears part of the diagonal tensile stress and fixes the position of the stressed reinforcement, and is often used in beams and columns. Load-bearing with negative reinforcement generally refers to the reinforcement of the load-bearing part of the beam to offset the negative bending moment, commonly known as load-bearing reinforcement. Generally, the bending moment of structural members is divided into positive bending moment and negative bending moment, and the steel bar equipped to resist negative bending moment is called negative reinforcement. Stress bars are steel bars that bear tensile stress and compressive stress. Put it in the next row, mainly to emphasize. The reinforcement is placed on the steel bar to transfer the force evenly to the steel bar. The distributed reinforcement appears in the slab, arranged inside the reinforcement and perpendicular to the reinforcement. Vertical bars and fixed stirrups are arranged on both sides of the outer edge of the compression zone of the beam to form a steel skeleton.