Name: Steel strand for prestressed concrete( steel strand for mining cable bolt)

Introduction: Prestressed steel strands are stranded steel cables consisting of 2,3,7 or 19 high-strength steel wires and are stress-relieved(stabilized) for prestressed concrete or similar applications.

The main characteristics of prestressed steel strands are high strength and good slack performance, and they are straighter when unfolded. Common tensile strength rating is 1860Mpa, and strength levels such as 1720, 1770, 1960, 2000, 2100Mpa. The yield strength of this steel is also very high.

Classification

According to the number of steel wires in a steel strand: 2 wire steel stranded, 3 wire steel stranded, 7 wire steel stranded and 19 wire steel stranded.

According to the surface shape, it can be divided into: smooth steel strand, scored steel strand, compact steel strand(compact), epoxy resin stranded wire, etc.

It can also be categorized by diameter, or intensity level, or by standard.

Specification

The general meaning is that "a bundle of steel strands consists of 15 roots of 7-wire diameter 5mm steel strands (each with a total diameter of about 15.24mm, dimensional deviation +0.40 -0.20; each wire diameter is about 5.0mm). The general cross-sectional area is calculated according to 140mm^2, and the theoretical breaking value is 140*1860=260.4kN. According to the pre-stress of 60%-65%, the tensile force can be 156.24-169.26kN.

Material

The high-carbon steel wire rod is subjected to surface treatment, cold-drawn into steel wire, and then a certain number of steel wires are twisted into a strand according to a steel strand structure, and then subjected to a stress-relieving stabilization process. To extend durability, there may be metal or nonmetal coatings on the wire, such as galvanizing, epoxy coating, etc. In order to increase the grip strength of the concrete, the surface may be scored, etc. The die-drawn prestressed steel strands undergo a mold compression process after stranding, the structure is more compact, and the surface layer is more suitable for anchor gripping. Unbonded steel strands are made of ordinary prestressed steel strands, coated with anti-corrosive grease or paraffin and then coated with high density polyethylene (HDPE).