How many categories are anchors divided according to their anchoring performance?

Anchors are divided into two categories according to anchoring performance: Category I Anchors: Suitable for prestressed concrete structures subject to dynamic and static loads ； Category II Anchors: It is only applicable to bonded prestressed concrete structures and the anchors are located in locations where the stress of the prestressed tendons does not change significantly. 　 In addition to the static load anchoring performance, Class I anchor assemblies must also meet the fatigue performance test with a cycle number of 2 million times. If used in seismic structures, it should also meet the cyclic load test of 50 cycles. In addition to the above, the anchorage should also have the following properties: 1. When the prestressed anchor assembly reaches the measured ultimate tensile force, all parts shall not have visible cracks or damage, except for phenomena permitted by the anchor design. ； 2. In addition to meeting the requirements of graded tensioning and supplementary tensioning processes, it should also have the ability to relax prestressed tendons. ； 3. Grouting holes should be provided on the anchor or its accessories, and the grouting holes should have a cross-sectional area that allows the slurry to flow smoothly. The on-site acceptance of anchors is the same as the clamps in the pre-tensioning method.