Pre stressed steel strand is a stranded steel cable composed of 2, 3, 7, or 19 high-strength steel wires, which have undergone stress relief treatment (stabilization treatment) and are suitable for prestressed concrete or similar purposes. Today, the manufacturer of pre stressed steel strand equipment will introduce its usage precautions.
（1） Storage:
Pre stressing steel should be stored in a dry warehouse. Outdoor and on-site storage. Sleepers should be installed on the ground, and direct contact with damp ground is strictly prohibited. They should be covered with tarpaulins or rain shelters to shorten the storage period as much as possible. In special environments, rust proof packaging should be used in ordering. The surface rust of prestressed steel does not affect its use, but the visible pitting caused by rust will affect its mechanical properties.
（2） Lifting:
The lifting of prestressed steel should be carried out sequentially, with orderly stacking and gaps left. Unbonded prestressed steel bars should be lifted in parallel with three brown rope eyelets, and direct lifting with steel wire ropes is strictly prohibited. Coiled steel strands should be lifted using forklifts or specialized lifting tools to prevent the steel strip from breaking and causing loose packages.
（3） Usage:
1. It is strictly prohibited to use any form of heating deformation measures in the use of prestressed steel to avoid reducing the mechanical properties of prestressed steel.
2. Welding is strictly prohibited during use, as the strength of the welding point is much lower than that of the steel itself, which can easily cause wire breakage at the welding point during tensioning.
3. The cutting of prestressed steel should use toothless (grinding wheel clamp). The use of electric or gas welding for cutting can easily damage the surface around the steel. Simultaneously causing local heating at the end, resulting in a significant decrease in performance.
4. When prestressed steel wire adopts cyclic reinforcement, its bending radius shall not be less than three times the diameter of the steel wire.
5. The steel strands packaged in rolls without shafts should be pulled out from the inner ring in an upright position, and the extracted steel strands should be spring-loaded and automatically straightened. Tapping direction: after tapping, the spiral direction of the spring shape is consistent with the twisting direction of the stranded wire, otherwise Fried Dough Twists or confusion will occur.
6. The twisting direction of steel strands is generally left twisting, and when using right twisting, it should be specified in the contract, otherwise it will directly affect the coordination with the anchor.
7. The quality of prestressed steel wire heading is not directly related to the quality of the steel wire itself, but excessive strength will be detrimental to the quality of the steel wire heading. Therefore, when choosing heading anchoring, you should explain it to the ordering company in the order.
（4） Acceptance:
1. The acceptance of prestressed steel should be carried out in accordance with relevant national standards, and the testing instruments should be national legal measuring instruments and comply with the provisions of the testing standards.
2. If quality problems occur during acceptance, attention should be paid to checking whether the following items comply with regulations:
(1) Has the latest national standards and testing methods been selected for acceptance.
(2) Is the tonnage of the selected testing machine appropriate; Whether the measurement is accurate; Whether the steel fracture is stuck; Whether to use nominal area to calculate strength.
(3) Whether the bending clamp of the bending testing machine complies with national standards, and whether the surface smoothness, hole height, and bending angle of the clamp meet the standards.
(4) The determination of the elongation of steel should be carried out using sharp and standard marking distance tools, and there should be no damage to the surface of the steel.
(5) Whether the steel itself has severe rust or artificial surface damage caused by storage.
（5） Setting out:
Pre stressing steel must be laid out using a wire laying machine before use.
The above is today's content. When using it, you can refer to the pre-stressed steel strand equipment manufacturer's above content for placement.