Post-Tensioning Duct Manufacturing
ASZ GRUP manufactures flat and round metal ducts used in post-tensioning systems at its production facility in Gölbaşı/Ankara. Ducts form the channels for post-tensioning strands within the concrete, allowing free strand movement and grouting after stressing.
Our production facility has a daily capacity of 5,000 metres and offers solutions in various diameters and wall thicknesses to meet project requirements.
Duct Product Brochure
Download our catalogue for detailed information on our flat and round duct products, technical specifications and manufacturing processes.
Product Range
Flat Duct
Flat ducts manufactured from galvanized steel sheet serve unbonded post-tensioning systems on building and bridge projects. Various width and height options are available.
Round Duct
Round ducts produced to EN 523/524 Class 2 are ideal for bonded post-tensioning systems on bridge, viaduct and cylindrical structure projects. EN 524 quality control tests are performed after manufacturing.
Round Duct — EN 523/524
Round ducts are manufactured and tested in compliance with EN 523 production and EN 524 quality control requirements.
5,000 m/Day Capacity
We meet large-project duct demand on schedule with high production capacity.
Quality Control
Stiffness, watertightness and dimensional tests per EN 523 and EN 524 are applied to round ducts.
Multiple Diameter Options
Various internal diameter and wall thickness options are available to suit project requirements.
Our Quality Control Process
Comprehensive quality control tests per EN 523 and EN 524 are applied in round duct production. The following tests are performed on each production batch:
- Lateral stiffness test (EN 524-3) — Shape stability against concrete pressure.
- Dimensional checks (EN 524-2) — Internal diameter, wall thickness and tolerance measurements.
- Watertightness test (EN 524-4) — Verification that injection grout does not leak outside the duct.
- Flexibility test (EN 524-5) — Duct performance in curved zones.
- Tensile strength test (EN 524-6) — Durability of duct connection points.
Our Production Facility
Our production facility in Gölbaşı/Ankara operates with modern machinery and an experienced production team. Continuous quality control in round duct manufacturing ensures EN 523/524 compliance.
- 5,000 metres per day production capacity
- Flat duct and EN 523/524-compliant round duct production line
- Production in various diameter ranges (40 mm — 130 mm internal diameter)
- Continuous quality control and test laboratory
Precast Duct Sales References
We serve precast and construction companies as a reliable supplier of flat duct and EN 523/524-compliant round duct.
| No. | Work Type | Company | Duct (m) | Year |
|---|---|---|---|---|
| 1 | Duct Sales | ILGAZ PREFABRİK | 2.072 | 2025 |
| 2 | Duct Sales | ÖZ MESA PREFABRİK | 1.890 | 2025 |
| 3 | Duct Sales | D-R PREFABRİK | 1.800 | 2025 |
| 4 | Duct Sales | SOM PREFABRİK | 3.400 | 2025 |
See our products page for technical details and diameter/thickness options for our duct products.