In a post-tensioned structure or member, a permanent anchoring device used to maintain the tension of a prestressed tendon and transfer it to concrete. Anchors can be divided into two types: (a) Tensioned anchorages: anchorages that can be tensioned at the ends of prestressed tendons; (b) Fixed anchorages: installed at the ends of prestressed tendons, usually buried Into the concrete and not used for tensioning anchors. The standard for pre-stressed anchors is: National Standard of the People's Republic of China (GB/T 14370-2000)

Application of anchorage:

Highway bridges, railway bridges, urban interchanges, urban light rails, high-rise buildings, water conservancy and hydropower dams, port terminals, rock body slope protection, foundation reinforcement, tunnel roof anchors, prestressed grids, subways, large-scale buildings, Warehouse buildings, tower buildings, heavy lifts, intermittent advancement of synovial membranes, bridge tunnel pushing, large containers and ships, sleepers, replacement of bridge bearings, reinforcement of bridges and buildings, reinforcement works, anti-magnetic and anti-corrosion projects (fiber anchors ), carbon fiber reinforcement, first beam field construction, external prestressed engineering, cable stays, suspension cables, etc.

At present, the commonly used anchorage specifications in the country are: (a) M15-N anchors. M stands for anchorage (the first letter of the Pinyin for Pinyin); 15 stands for stranded wire with the specification of 15.24 for steel strands, (usually commonly used steel strands with a strength of 1,860 MPa, 15.24 Strand);- N refers to the number of steel strands to be worn. (b) M13-N anchors. M stands for anchorage (the first letter of the pinyin for Pinyin); 13 stands for strand of the steel strand with the size of 12.78, (usually the commonly used steel wire strand of 13.78 for 1860MPa grade);- N refers to the number of steel strands to be worn.

Common system classification of anchorages: (1) Conventional cylindrical anchorages. Specifications and models are expressed as: M15-N or M13-N; this anchorage has good anchorage performance and self-anchoring performance. Tension is generally adopted through heart type jack (2) cuboid flat anchor. The specification and model are expressed as: BM15-N or BM13-N (B, the first letter of the Pinyin pinyin, representing the meaning of the flat anchorage); The flat anchorage is mainly used for the lateral prestressing of the bridge deck, hollow slab, low height The box girder makes the stress distribution more uniform and reasonable, and further reduces the thickness of the structure. (3) grip wrapped anchors. The specification and model are expressed as: M15P-N or M13P-N; it is applicable to the situation where the design of the end fabric of the component end is in high stress or the space in the end is limited. It uses an extruder to press the extrusion sleeve on the steel strand. Wrapped anchors, which are embedded in concrete and arranged as required, are stretched after the concrete is set to its design strength.