Production of Post Tensioning Accessories (Anchor Head & Wedge)
This simple video captures some process in our production of post tensioning accessories, namely Anchor Head and Wedge.
Anchor Head (also commonly known as Wedge Plate) is an important part of the post tensioning system. It works in tandem with the Wedge that holds the individual tensile element. The prestressing load is then transfer to the Bearing Plate. For some small tendon sizes, this prestressing force can be transferred directly to the structure without the need of Bearing Plate.
In the case of some mono anchorage system, the Wedge will hold an individual tensile element directly to the Bearing Plate.
Anchor Head and Wedge is subjected to Static Load and Fatigue (Reliability) Test. Hence its design and production quality control is of paramount importance.
Static Load Test requires the Anchor Head and Wedge to hold to a specific percentage (>95%) of the tensile element ultimate strength with a minimum elongation (>2%), with without premature failure of anchorage components, without undue deformations in the components, and without disproportionate relative movements between tensile elements and anchorage components.
As for Fatigue Test, the Anchor Head and Wedge have to go through 2 million cycles of fatigue loads (dynamic strength, 80MPa) without exceeding a specified percentage loss of tensile element cross section (<5%).
We hope this video provides some insight of our production process and gives our operators a better understanding of our commitment to quality control.