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Post Tension System of Investment Casting in China


What is post tension system?

Post-tension is a way of reinforcing concrete or other material with high-strength steel strands or bars. Its applications include buildings, parking structures, bridges, rock and soil anchors, ect. In many cases, post tensioning allows construction, which would otherwise be impossible due to either site constraints or architectural requirements. Post-Tensioning Systems are world renowned for reliability and performance, most suitable for all applications in post-tensioned construction. They embrace the entire spectrum from bridge construction and buildings to civil applications, above and below ground.

Why post tensioning?

Architects, Structural Engineers, General Contractors, Real Estate Developers, and Owners incorporate post-tensioning systems on their projects in order to achieve economy, efficiency, quicker construction and lower lifetime cost of the structure. Why? Because Post-Tensioning enhances concrete strength both under compressive and tensile stresses.

How does post tension system work?

Post-tensioning is where prestress is permanently introduced into the concrete structure after the concrete has hardened. By stressing properly positioned high strength prestressing tendons, Post-Tensioning System introduces constructive stress into the concrete structure, thus increasing overall productivity and usage efficiency of construction materials.

Post-tensioned systems should only be designed and installed by specialist companies. Designing the shape of the PT layout and specifying the right system is a vital stage in the process and requires sound engineering consideration in order to maximize the benefits for all the stakeholders in a project. For example, in the case of ground slabs, design of the post-tensioning involves the careful analysis of the loads applied to the slab, the interaction between the slab and the ground that supports it, restraint forces and temperature effects. The techniques can be extended to deal with weak ground where the ground acts as the permanent formwork and the slab bridges between piles and/or ground beams. This avoids expensive ground improvement work. Work on applying the post-tensioning system can begin after any formwork or bottom reinforcement has been installed. Typically, for a bonded system, ducting will be laid out first, then strands will be installed with the help of a strand-pushing machine and end anchorages will be placed. Concrete placement follows next. When the concrete has attained its minimum strength, the strands are anchored in a common anchorage device and stressed with a large, multi-strand jack. When the jack reaches the correct load, it releases the tendon. The tendon then retracts slightly, activating the anchoring system and creating a tight lock on the tendon. The anchor maintains the applied force in the tendon and transfers it to the surrounding concrete. The duct is then filled with a cementitious grout that provides corrosion protection to the strand and bonds the tendon to the concrete surrounding the duct.

What kinds of investment castings does my foundry make for post tension system?

*Bonded Flat slad anchors
*Unboned monostrand anchors
*Anchor head

My foundry normally makes such castings for post tension system with investment casting material gray iron 250. Investment casting process will ensure post tension system parts in net shape and reduce machining job, which will be helpful for cost saving. Tooling will first be made before production, as the quantity for such parts is large, so we suggest metal mould. Except casting, machining service is also available in our foundry.

Will the quality of investment cast post tension parts be assured?

Quality assurance is also very important for our clients, common quality problems of products are low hardness, internal defects (gas cavity).When sample is ready, we will cut a small piece from sample body and test the hardness first to check whether our product is qualified. Regarding internal gas cavity, we could test by X-ray.

Key benefits of post tension castings from our foundry:

*We are the end manufacturer, so we could cast out high quality products.
*The production cost for post tension castings is low. So correspondingly, the unit price will also not high.
*Our allocative material will be unique, which will ensure long working life of post tension castings.
*Expect post tension castings, we could also custom other investment castings for civil applications according to our customer's drawing or sample, so as to meet various need of clients.




Liaoning Borui Machinery Co., Ltd. All rights reserved.
Add: No.1-4-6, Jianshe Road, Qianyang, Donggang City, Dandong, Liaoning, China 
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