PC Wire, Prestressed concrete steel wire, is a special steel wire made from carbon steel,which can be used in prestressed concrete structure or prestressed steel structure of a steel wire.
Prestressed steel wire can be classified according to diameter, strength grade, surface coating or cross-sectional morphology:
1, according to the diameter can be classified as: 4mm, 4.8mm, 5.0mm, 5.1mm, 6.0mm, 6.25mm, 7.0mm, 7.8mm, 8.0mm, 9.0mm, 9.5mm, 10.0mm, 11mm, 12mm and so on.
2, according to the intensity level can be classified as: the strength of prestressed steel 800 ~ 1200MPa; high-strength prestressed steel 1470MPa, 1570MPa, 1670MPa, 1770MPa and 1860MPa and so on.
3, according to the surface coating types can be classified as: no coating of prestressed steel wire, epoxy resin coated with prestressed steel wire and galvanized prestressed steel wire.
4, according to the surface morphology can be classified as: optical round prestressed steel, spiral rib (spiral ribbed or helix grooved) prestressed steel wire (L or D), crushed (crimped) prestressed steel wire or indented Steel wire (two-sided notch, three-side notch, four side notches) and so on.
5, according to the treatment process can be classified as: cold-drawn prestressed steel wire (no relaxation performance requirements) and low relaxation prestressed steel wire
Second, Production method
Cold drawn (cold drawn) prestressed steel wire with high-quality high-carbon steel wire rod (high carbon wire rod) after surface treatment after cold drawn from the carbon content of steel in the 0.6-0.9 range of choice, to go through acid before drawing Phosphate or other forms of surface treatment, cold-drawn cross-sectional area will generally be reduced by 50-85%, through the principle of cold work hardening to improve strength. Cold-drawn prestressed steel wire becomes a low-relaxation prestressing wire, such as Stabilizing, to obtain a low relaxation characteristic and remarkably improve the yield strength, elongation and straightness. If galvanized to become galvanized prestressed steel, galvanized after stabilization of the steel wire is called low relaxation galvanized prestressed steel wire. The wire is generally delivered in coil form and, when applied to a railway sleeper, can be cut into bundles as required.
Prestressed steel wire diameter is generally in the range of 4-12 mm, the current China 5 mm and 7 mm specifications.
The high strength of this material mainly in the axial direction, the radial was significantly lower. Heat to 400 degrees or higher, the relaxation performance and strength properties will be significantly damaged. Cold-drawn prestressed steel wire used in the pipeline should pay attention to check its resistance to stress corrosion. When galvanized steel wire is used, it should not be completely relied upon for its corrosion resistance. The whole cable system should have other protective measures.
Cold-drawn prestressing is generally used for pipes, especially those made with PCCP process. Low relaxation prestressed steel wire widely used in railway sleeper and prestressed concrete poles, a small amount for building components, prefabricated beams have been basically not used. Low relaxation galvanized prestressed steel wire is often used in cable stayed bridges (cable stayed bridge) bridge, steel pipe arch suspension rod (tie rod) and the production of large-span construction for the prestressing cable, without stabilization of the plating Zinc wire is generally used for suspension bridges.