The Main Characteristics of Prestressed Steel Strand
The prestressed steel strand is a stranded steel cable composed of 2, 3, 7, or 19 high-strength steel wires, and has undergone stress-relief treatment (stabilization treatment), suitable for prestressed concrete or similar purposes. The main characteristics of prestressed steel strands are high strength and good relaxation performance, and they are relatively straight when unfolded.
The tensile strength grade of common prestressed steel strands is 1860 MPa, and there are strength grades such as 1720, 1770, 1960, 2000, and 2100 MPa. The yield strength of this steel is also very high. According to the number of steel wires in a steel strand: 2 wire steel wire, 3 wire steel wire, 7 wire steel wire, and 19 wire steel wire.
According to its appearance, it can be divided into smooth steel strand, indented steel strand, compact steel strand, epoxy resin coated steel strand, etc. It can also be classified according to diameter, strength grade, or specification. In the specification and list table, we often see that there are prestressed steel strands of 15-7Φ5, 12-7Φ5, 9-7Φ5, etc.
Taking 15-7Φ5 as an example, 5 indicates a single steel wire with a diameter of 5.0mm, 7Φ5 indicates that 7 such steel wires form a steel strand, and 15 indicates that each bundle of steel strands consists of 15 7Φ5 steel strands. The overall meaning is a bundle of steel strands is composed of 7 steel wires with a diameter of 5mm (each bundle has a total diameter of about 15.24mm, dimensional tolerance +0.40 -0.20, and each steel wire diameter is about 5.0mm) steel strands.