Production process of indented steel stranded wire for prestressed concrete

Abstract

The invention relates to the technical field of steels for prestressed concrete articles in construction industry. 1x7 structure and 1x19 structure that is developed in later period are the steel stranded wires made of smooth, round steel wire twists. While usage, smooth, round core wires are in non-effective contact with edge wires, which is extremely liable to production of slide movement and retraction of edge of the core wires, lessens bondability and causes reduced overall tensile strength of the steel stranded wires. To overcome defects in such a structure, tested production of the indented steel stranded wire has been launched. The invention invents the production process of the indented steel stranded wire for the purpose of realizing the indented steel stranded wire products, which comprises: acid cleaning with 80-180 g / l concentration of hydrochloric acid, phosphatization with 2 to 3 ml concentration of nitrite as an accelerating agent, saponification with 15% to 22% of soap flakes, drying by the temperature of 90 to 100 DEG C, cold-drawing the smooth, round steel wires, indenting the steel wires online through three-roller 120 degrees, twisting, application of tension intermediate frequency stabilization, wire coiling and package of finished product. Employing the process realizes the issues to be solved in the indented steel stranded product, and plays a reference function to the production of steel stranded wire product having large specification, high intensity and low loosening performance; and the product can be extensively applied to high-rise, long-span bridge, mine support and the like.

Description

technical field [0001] The utility model relates to the technical field of steel used for prestressed concrete products in the construction industry, in particular to the technical field of production technology of steel strand steel bars used as reinforcement in prestressed concrete components. technical background [0002] In the prestressed concrete components used in the construction industry, in order to increase the mechanical properties of the components such as compression resistance and earthquake resistance, steel strands are used as reinforcement. At present, the 1×2, 1×3 and 1×7 steel strands in the national standard GB / T5224-2003 "Steel Strands for Prestressed Concrete" are composed of 2, 3 and 7 smooth round steel wires respectively. Twisted standard steel strands. [0003] For example, the 1×7 structural steel strand is twisted by 7 smooth round steel wires. In the construction of pretensioned prestressed concrete components, the 6 twisted and deformed smooth...

AI Technical Summary

Problems solved by technology

[0004] There are two major deficiencies in this structural steel strand. One is that the standard steel strand with a structure of 1 × 7 is ineffectively contacted between the light round core wire and the six light round steel wires at the edge, so only relying on the non-effective contact Friction produces back pressure stress on concrete components. After the steel strands are stretched in pre-tensioned prestressed concrete components, it is very easy to cause the edge of the core wire to slip and retract, resulting in a reduction in the stress of the core wire or a complete loss of stress.

The second is that in fact, the 6 smooth round steel wires on the side of the steel strand work, and the middle core wire fails, resulting in a decrease in the overall tensile strength of the steel strand, a decrease in stress, a decrease in the performance of concrete components, and a reduction in the relationship between the steel strand and the concrete. Grip

Images