Do you know about PC Spiral Rib Steel Wire?

Prestressing Technology and PC Steel Wire Types

The core principle of prestressing technology is to apply tension to steel reinforcement in advance. PC spiral rib steel wire is mechanically stretched to 70%–80% of its ultimate strength, and the resulting retraction force induces permanent compressive stress in the concrete. This pre-compression offsets tensile stresses generated by external loads, enhancing the overall strength and durability of the structure.

PC steel wire, made from high-quality carbon steel, is specifically designed for use in prestressed concrete structures. It is available in three main types:

• Plain PC Wire – smooth surface for standard prestressed applications.

• Spiral Rib PC Wire – features spiral ribs for improved bond with concrete.

• Indented PC Wire – surface indentations that further enhance concrete adhesion and load transfer.

PC spiral rib steel wire is manufactured from high-strength steel wire and formed into a spiral configuration. Its surface features a three-dimensional spiral rib structure, with rib heights ranging from 0.2 to 1.0 mm. The ribs are arranged in continuous spiral protrusions, with a spiral angle of 60°–80° and a staggered double-helix layout.

This design ensures high strength and low relaxation while providing excellent bond performance with concrete. Supplied in coils and available in long lengths, the PC spiral rib steel wire is efficient to use, reduces material consumption, and is ideal for prestressed concrete applications requiring superior structural integrity.

Production Process of PC Spiral Rib Steel Wire

1. Raw Material Inspection – High-carbon steel wire rods are carefully inspected to ensure they meet strict quality standards.

2. Surface Treatment – Processes such as pickling and phosphating remove surface impurities and enhance the wire’s surface performance.

3. Semi-Finished Product Drawing – Wire rods are cold-drawn to achieve the required semi-finished dimensions.

4. Spiral Rib Drawing – Using specialized rotating equipment and spiral dies, the semi-finished wire is formed into the spiral rib structure.

5. Stabilization Treatment – Wires are stabilized at 380°C–400°C to relieve internal stress, improve dimensional stability, and enhance relaxation performance.

6. Wire Collection, Inspection, and Acceptance – The treated steel wire is collected and subjected to thorough performance inspections and acceptance tests in accordance with industry standards.

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Performance Characteristics of PC Spiral Rib Steel Wire

• High Strength – Nominal tensile strength ≥ 1570 MPa, providing robust prestress for concrete structures.

• Excellent Bonding Performance – The spiral rib design enhances the bond between the steel wire and concrete, ensuring they work together efficiently.

• Low Relaxation – For an initial force equivalent to 70% of peak stress, the 1000-hour stress relaxation rate ≤ 2.5%; for 80% of peak stress, the 1000-hour stress relaxation rate ≤ 4.5%.

• Good Straightness – When a 1-meter steel wire is placed on a flat surface, the chord-to-inner natural sagittal height deviation does not exceed 20 mm for all wires, ensuring precise installation and consistent performance.

Application Fields of PC Spiral Rib Steel Wire

• Bridge Engineering – Used in bridge beams, piers, and other structural components to enhance load-bearing capacity and improve crack resistance.

• Construction Engineering – Ideal for foundations of high-rise buildings, roof trusses of large-span structures, and other critical elements to increase structural stability and durability.

• Rail Transit – Applied in railway sleepers, subway tunnels, and similar infrastructure to ensure track smoothness, stability, and extended service life.

• Water Conservancy and Hydropower Engineering – Utilized in hydraulic structures such as dams and reservoirs to enhance impermeability and resist cracking.

PC steel wire is available in a variety of diameters to meet diverse construction needs, with common sizes including 4 mm, 4.8 mm, 5 mm, 7 mm, 9 mm, 11 mm, and 12.7 mm. The appropriate diameter is determined by factors such as expected load, structural element dimensions, and specific engineering design requirements.

The tensile strength of PC steel wire varies according to project demands, typically ranging from 1570 MPa to 1860 MPa, including options of 1570 MPa, 1670 MPa, 1770 MPa, and 1860 MPa. Higher-strength wires provide increased load-bearing capacity, enabling the construction of stronger, more durable concrete structures.