Advantages and functions of high-strength prestressed steel strand

High-strength prestressed steel strands are widely used in many industries. In the 1950s, prestressed concrete steel strands entered the practical application stage. However, the basic principle of prestressing is not only applicable to steel strands, but also has been applied in many aspects in ancient times. Hoop reinforcement is a good example. It applies a certain pressure to the loose wedge plate, forming a bucket and withstanding sufficient lateral pressure. This is an early prestressing principle.

High-strength prestressed steel strand structure The advantages and application of prestressing in concrete components are mainly to overcome the shortcomings of low tensile strength of concrete and make full use of high-strength steel. When the tensile stress of the reinforcing steel reaches 250 MPa, and the crack width reaches 0.2-0.3 m, the durability of the component will decrease, and it is not suitable for high-humidity and corrosive working environments. The role of prestressed steel strand is to generate pre-compression stress in the component before loading, thereby controlling the tensile stress level of the component, or even making the component under compression. In order to avoid early cracking of reinforced concrete components, high-strength steel and high-strength concrete are fully utilized to improve their performance and durability.

The main results are as follows:

（ 1) Due to the effective use of high-strength steel strands and concrete admixtures, compared with ordinary reinforced concrete, prestressed concrete steel strands can be used to make slender load-bearing structures with large spans and small self-weight;

（ 2) Prestressed steel strands can improve the usability of concrete structures, effectively prevent concrete cracking, or at least limit the crack width to a harmless level, and improve the durability of the structure;

（ 3) Under the action of load, even if partial prestress is applied, the deformation of the structure can be controlled to a very small state;

（ 4) As long as the steel reinforcement strain is less than 0.01%, overload cracks can be closed again after unloading.

Construction methods of high-strength prestressed steel strands? First, install prestressing pipes, install corrugated pipes using materials such as anchor plates and prestressed plastic corrugated pipes, and determine the accurate position of the corrugated pipes during construction. The top surface of the box or the support platform is used as the steel wire cutting point. The second method of cutting the steel wire with a four-wheel saw is the single-end tension method. The prestressed anchor rod uses P-type anchor rod fixation to ensure the construction quality of the P-type anchor rod. When the raw materials enter the site, a vernier caliper should be used for size matching tests and inspections, including the extrusion spring, extrusion head, and the complete steel strand after extrusion.

According to P-anchor design drawings, the nominal position of the anchor plate is fixed by the root of the P-chain anchor and the anchor plate. Fix the formed anchor end. Install the anchor ring. After concrete pouring and curing, the anchor ring should be installed. The bridge steel strand manufacturer believes that the standard has been completed. After the concrete reaches the design strength, install the jack and start the tensioning construction. Then carry out prestressed tensioning construction. Afterwards, the