Introduction to the Four-piece Set of Prestressed Anchorage
Prestressed anchorages are widely used in bridge engineering and construction industries, such as bridges, subway culverts, slope reinforcement, and high-rise buildings. Prestressed anchorages are essential materials in these industries. In addition, depending on the specific location where prestressed anchorages are used, they are generally divided into different types of prestressed anchorages. The most common prestressed anchorages generally have a four-piece set, so what are the four-piece sets?
1. Anchor head
Round prestressed anchorages: The specifications and models are often expressed as M15-N or M13-N (M is the first letter of anchorages in Chinese). This anchor has good anchoring performance and self-anchoring performance. Generally, a multi-strand center hole jack is used to stress the round anchorage.
Cuboid flat anchorage: The specification model is often expressed as BM15-N or BM13-N (B is the first letter of flat anchorage in Chinese). Flat anchorages are mainly used for lateral prestressing of bridge decks, hollow slabs, and low-height box girders to make the stress distribution more uniform and reasonable, and further reduce the thickness of the structure.
A principle used by the wedge-type prestressed anchorage is the principle of taper hole wedging to anchor the steel strand. That is, the steel strand is anchored in the anchor hole. When we use the tensioning jack to pre-tension it, after reaching a certain design tension value, then the tensioning jack performs a slow release. At this time, the wedge will slowly retract into the hole of the anchor head, and a kind of prestress will be formed at this time.
3. Bearing Plate
The bearing plate is a steel plate or cast iron plate needed to anchor the prestressed tendons during prestressed construction. Among them, the bottom structure of the bearing plate is flat, and the shape is mostly square or round. Its function is to spread the prestress during tension into the beam concrete.
4. Spiral Reinforcement
Spiral reinforcements are also called screw hoops, stiffeners, and anti-collapsing tendons. Spiral reinforcements are to improve the local compressive strength of concrete. The anchor has great local pressure on the concrete behind it during post-tensioning. In order to prevent the concrete from being crushed, spiral reinforcements are arranged behind the anchorage to increase the compressive strength.
To sum up, it is a simple introduction to the four-piece set of prestressed anchorage. These materials usually appear in a complete set during the construction process, and they are also widely used in construction.