Cold rolled twisted steel bars
Cold-rolled twisted rebar is a new type of steel product developed based on cold-rolled ribbed rebar. It uses a cold-rolling process to twist the rebar, creating spiral ribs and a twisted shape on the surface, further enhancing its bonding and mechanical properties with concrete. Compared to conventional cold-rolled ribbed rebar, cold-rolled twisted rebar has higher yield strength and tensile strength, generally exceeding 550 MPa. Its unique twisted shape significantly enhances its mechanical bond with concrete, effectively transferring stress and reducing structural deformation. Furthermore, cold-rolled twisted rebar exhibits excellent ductility and plastic deformation under stress, preventing brittle failure. It is a safe and reliable steel reinforcement material for construction.
The production process of cold-rolled twisted rebar adds a twisting step to the production process of cold-rolled ribbed rebar, and mainly includes raw material preparation, cold rolling, twisting, and cutting to length. First, high-quality low-carbon hot-rolled wire rod is selected as the raw material. After strict quality inspection, it enters the cold rolling unit and is rolled by rollers to form rebar with specific ribs and dimensions. Subsequently, the rolled rebar enters the twisting equipment and is twisted under a certain torque, so that the rebar produces a continuous spiral twist along the length direction. The twisting pitch and angle must be precisely controlled according to the diameter and performance requirements of the rebar. During the twisting process, the internal structure of the rebar is further refined, and the mechanical properties are improved. Finally, the twisted rebar is cut into fixed lengths, packaged, and quality tested to ensure that the product meets the relevant standards.
Cold-rolled twisted steel bars are mainly used in construction projects for reinforcement of concrete structures that bear static loads, such as floor slabs, roof slabs, walls, beams and columns. In cast-in-place concrete floor slabs, the use of cold-rolled twisted steel bars as load-bearing and distribution steel bars can significantly improve the floor slab’s crack resistance and load-bearing capacity, reduce the amount of steel bars used, and lower the project cost. Due to its excellent bonding properties with concrete, it can effectively resist the vibration and deformation of the structure under earthquake action, thereby improving the seismic performance of the building. In the production of prefabricated components, such as prefabricated hollow slabs and prefabricated composite slabs, cold-rolled twisted steel bars facilitate automated production due to their high dimensional accuracy and easy processing, thereby improving the production efficiency and quality stability of prefabricated components.
The following technical points should be noted during the application of cold-rolled twisted steel bars: During the design phase, the diameter, strength grade and twisting parameters of the cold-rolled twisted steel bars should be reasonably selected according to the stress characteristics of the structure and the use environment to ensure that they meet the design requirements. During the construction process, the binding and installation of steel bars should be carried out strictly in accordance with the specifications to ensure that the spacing of the steel bars, the thickness of the protective layer, etc. meet the design requirements to avoid affecting the structural performance due to improper construction. Since the cold-rolled twisted steel bars have been twisted, their end anchoring performance is better and generally do not require additional hooks, but reliable anchoring measures should be taken in areas with greater stress. During the concrete pouring process, the vibrator should be prevented from directly colliding with the steel bars to prevent the steel bars from deforming or shifting, and to ensure that the steel bars play a normal stress-bearing role in the concrete structure.
With the continuous development and technological advancement of the construction industry, the production technology and product performance of cold-rolled and twisted rebar are also constantly improving. By optimizing the cold rolling and twisting process parameters, manufacturers have further improved the strength and toughness of the rebar and developed higher-strength cold-rolled and twisted rebar products to meet the needs of large-scale building structures. At the same time, to meet the requirements of green building and sustainable development, manufacturers are continuously improving production processes and adopting high-efficiency and energy-saving production equipment to reduce energy consumption and pollutant emissions. In the future, with the rapid development of prefabricated buildings and green buildings, the market demand for cold-rolled and twisted rebar will continue to grow, and its application areas will continue to expand, providing strong material support for the development of the construction industry.
