The Application and Precautions of Prestressed Anchorage
Prestressed anchorages must be the most familiar tool for people engaged in the bridge construction industry. It is an anchorage suitable for concrete prestressing during construction. Generally speaking, it is often used for bridge construction. Do you want to know more about this? The following is an introduction to “the application and precautions of prestressed anchorages”.
Where can the prestressed anchorages be used?
Prestressed anchorages are mainly used for anchorages used for prestressed tensioning in engineering construction. Next, let’s talk about the application range of prestressed anchorages, to help you learn more about anchorages.
Prestressed anchorages are widely used in public beams, iron beams, urban interchanges, urban light rails, high-rise buildings, water conservancy and hydropower dams, wharves, rock slope protection, and anchoring, foundation reinforcement, tunnel, and mine roof anchors, prestressed grids, subways, large buildings, warehouses, tower buildings, heavy lifting, sliding film intermittent propulsion, bridge and tunnel jacking, large containers and ships, sleepers, replacement of bridge supports, bridge and building reinforcement, steel reinforcement engineering, anti-magnetic and anti-corrosion engineering, carbon fiber reinforcement, pre-tensioned beam field construction, external prestressing engineering, stay cables, suspension cables, and other projects.
Precautions for the use of anchorages
1. Before using anchorages, you should be familiar with the operating methods of the tensioning system and the relevant prestressed construction specifications.
2. Before sampling the static load test, clean the anti-rust grease on the surface of the clip with gasoline, and wipe the wedge and anchor plate hole clean, otherwise, it will affect the performance of the static load test.
3. There are two types of anchorages: working anchorages and tool anchorages, and the two cannot be mixed.
4. When installing the anchorage, the working anchor plate should be aligned with the top of the anchor backing plate, and the wedge should be flush after installation. It can be tapped lightly with a special tool, but the wedge should not be damaged by heavy tapping.
5. During the construction period, the operator shall not move directly in front of the anchorage, and shall not strike the steel strands and anchorages forcefully.
Precautions for tensioning of prestressed anchorages
1. The steel strand must not be severely corroded. If there are rust pits and pitting, the strength of the steel strand will be reduced, and the wire will break during tension. In the anchoring area, the floating rust, cement grout, and sand on the steel strands should be cleaned up to avoid affecting the anchoring.
2. The anchor head and wedge must be properly kept at the construction site to prevent moisture and rust, especially if the teeth of the wedge are severely rusted, stop using them. Avoid sticking to mud and sand when using the wedge.
3. The stressing jack, oil pump, and oil pressure gauge should be calibrated before use. If the oil pressure gauge is bumped or replaced with a new gauge during use, it should be calibrated again. When the deviation between the tension and the design is large, the accuracy of the pressure gauge should be considered. The no-load run is strictly prohibited on the jack.
4. When using tool anchorages, be sure to apply a layer of paraffin wax on the outer cone of the tool wedge to facilitate the tensioning and retreating of the anchorage.
5. The steel strands between the tool anchorages cannot cross, otherwise, the anchoring performance will be affected.
6. During the period from applying the prestress to the end-capping, the operator shall not move directly in front of the anchorage, and shall not strike the steel strand and anchorage with force. When removing excess steel strands, it is recommended to use a grinding wheel to cut, and it is forbidden to use electric welding.