Benefits & Features
Introduction:
Prestressed steel strand is a twisted cable consisting of multiple (customizable) high-strength steel wires that have been stress-relieved (stabilized) and are suitable for prestressed concrete and similar applications.
The main characteristics of prestressed steel strand are high strength and good relaxation properties. It also maintains a relatively straight position when unwound. It is available in a variety of strength grades and has a high yield strength.
Classification:
Based on the number of steel wires in a strand, it can be classified as: 2-wire strand, 3-wire strand, 7-wire strand, and 19-wire strand.
Based on surface morphology, it can be classified as: smooth strand (uncoated), notched strand, die-drawn strand (compact), galvanized prestressed strand, and epoxy-coated prestressed strand.
It can also be classified by diameter, strength grade, standard, or raw material.
Material:
Prestressed steel strand is primarily made of cold-drawn high-carbon steel, with trace amounts of phosphate and lubricant residue on the surface. When strength is particularly high (e.g., 2300 MPa), alloying elements such as chromium are added. High-strength galvanized products can increase the silicon content.
Some prestressed steel strands made from carbon steel are coated with materials such as zinc, zinc-aluminum alloys, zinc-aluminum-magnesium alloys, epoxy resins, anti-corrosion greases, polyester, and high-density polyethylene sheaths.
Stainless steel can also be used for prestressed steel strands, with high-strength duplex stainless steel being preferred.
Applications:
Prestressed steel strands are primarily used in post-tensioned and pre-tensioned concrete projects, with bridge structures being the most common.
Formed-drawn steel strands are primarily used in hoisting projects, but are also used in projects such as nuclear power plants.
19-wire large-diameter steel strands are commonly used for mine support anchor cables.
Unbonded prestressed steel strands are commonly used in building slabs and some geotechnical anchor cables.
Galvanized steel strands are commonly used for bridge ties, cables, and external prestressing systems. Epoxy-coated steel strands have similar applications to galvanized prestressed steel strands and are suitable for projects requiring high durability.
