High-strength prestressing steel strand is a double-twisted strand composed of 2, 3, 7, or 19 high-strength steel wires. It is suitable for applications such as prestressed concrete. After stress relief (stabilization) treatment, let's learn about the characteristics of high-strength prestressing steel strand!

　　Classification of High-Strength Prestressed Steel Strands

　　According to the number of steel wires in a steel strand, it is divided into two-wire strands, three-wire strands, seven-wire strands, and nineteen-wire strands.

　　According to the surface morphology, it can be divided into smooth steel strands, notched steel strands, demolding steel strands (compact), epoxy resin steel strands, etc.

　　It can also be classified by diameter, strength grade, or standard.

　　High-Strength Prestressed Steel Strand Standards

　　In the description and table, model specifications such as 15-75, 12-75, and 9-75 prestressed steel strands are common. Taking 15-75 as an example, 15 indicates that the diameter of one strand is 15mm, 75 indicates that it is composed of 7 such steel wires, and the total diameter is approximately 15.24mm. The diameter of a single wire is approximately 5.0mm (steel bar composed of steel strands). The general cross-sectional area is calculated as 140mm^2, the theoretical breaking value = 140 * 1860 = 260.4kN, and according to the prestress standard of 60%-65%, it can withstand a tensile force of 156.24-169.26kN.

　　Materials of High-Strength Prestressed Steel Strand

　　It is made of high-carbon steel wire rod after surface treatment, cold-drawn into steel wire. To improve durability, the wire can be plated with metal or non-metal coatings such as galvanized or epoxy resin coatings. According to the steel strand structure, a certain number of steel wires are combined into strands, and then undergo a stress-relief stabilization process. After a single die compression process, the structure is more compact, and the surface is suitable for anchor grip. The production of unbonded prestressed steel strands uses ordinary prestressed steel strands. To improve the grip with concrete, the surface can have notches, etc. After twisting, the drawn prestressed steel strands are coated with anticorrosion grease or paraffin wax and then wrapped with high-density polyethylene (HDPE).

　　Characteristics of High-Strength Prestressed Steel Strand

　　The main characteristics of high-strength prestressed steel strand are high strength and good relaxation performance. In addition, it straightens when unfolded. The common tensile strength grade is 1860MPa, and there are also strength grades such as 1720, 1770, 1960, 2000, and 2100MPa. This steel also has high yield strength.

　　Applications of High-Strength Prestressed Steel Strand

　　In many post-tensioned and pre-tensioned engineering projects, galvanized steel strands are often used in bridge tie rods, cables, and external prestressing construction. Smooth steel strands are widely used prestressing steel. The removal of steel strands is mainly used in lifting projects and also in nuclear power projects. The uses of epoxy resin coated steel strands are similar to those of galvanized prestressed steel strands. Prestressed steel strand standard specifications.

　　Various countries have standards for high-strength prestressed steel strands, such as the Chinese standard GB/T 5224, the American standard ASTM A416, the British standard BS 5896, the Japanese standard JIS G3536, the Australian and New Zealand standard AS/NZS 4672, and the Brazilian standard NBR-7483, etc.