Our company mainly produces all kinds of prestressed intelligent tensioning equipment for bridge engineering, intelligent grouting equipment, tensioning jacks, anchors, electric oil pumps, corrugated pipe machines, extruders and so on.
What are equipments used in prestressing ?
1. Anchor and accessories
Commonly used anchor, fixture, side adapter. According to different anchoring methods, it can be divided into clamping type, supporting type, cone plug type and gripping type.
2. Corrugated pipe
Commonly used bellows are divided into plastic bellows and metal bellows according to material.
3. Jack
Common types of hydraulic jacks are pull rod type (YDL), through the core type (YDC), cone anchor type (YDZ), pedestal type (YDZ).
4. Tension Oil pump
Oil pump is the power source of prestressed hydraulic equipment. According to the driving mode is divided into manual electric, intelligent electric two.
Manual + electric drive pump:
5. Smart oil pump:
Prestressed intelligent tensioning system is suitable for a variety of working conditions, multiple strands of steel strand to achieve synchronous tensioning, single strands of steel strand to achieve simultaneous tensioning at both ends, using touch screen, electronic display of tensioning value, according to the set tensioning value, pause time, intelligent tensioning, improve the system, reduce redundancy, improve reliability, its accuracy can be controlled within 1.5%. Synchronous tension error < 2%.
6. Steel hinge line
In general, prestressed concrete steel hinge lines are used as prestressed tendons in bridge structures.
The main characteristics of prestressed steel strand are high strength and good relaxation.
7. The cable threading machine is mainly used for the cable threading during the post-tensioning construction of cast-in-place beam Bridges.
What are the two methods used for prestressing ?
Tension classification of prestressed concrete:
★ 1.Pre-tensioning construction technology
Definition: The concrete is poured first, and after the concrete is hardened, the prestressed steel bar is directly tensioned on the member, this construction method is called the post-tensioning method.
Threading the steel bars → stretching the steel bars → pouring and curing the concrete → cutting the steel bars.
(1) advantages:
simple production process, fewer processes, high efficiency, easy to ensure quality, at the same time because of the elimination of anchor and reduce the embedded parts, the cost of components is low.
(2) scope of application: mainly used in factory mass production, especially suitable for long-term production, small components.
post-tensioning
★ 2. post-tensioning construction technology
Pour the concrete member → cut through the prestressed steel → stretch the steel bar and anchor with the anchor tool → pressure grouting into the channel.
(1) advantages:
The prestressed steel bar is directly stretched on the member, there is no need for tension bench, so the post-tensioned member can be produced in the prefabrication plant or at the construction site. Large prestressed concrete components in the field production can avoid long-distance handling, so our country's large prestressed concrete components mainly use the post-tensioning method.
(2) disadvantages: long production cycle; It is necessary to use working anchors to anchor prestressed tendons, which consumes more steel and costs more. The operation is more complicated than the pretensioning method, and the cost is generally higher than the pretensioning method.