Stressing and Detensioning

To perform their function the steel wires have to be fixed on the reaction beams and prestressed before concrete casting. The stressing can be done in two different ways, single or multi stressing and in both cases the wires are fixed on the reaction beam by means of anchor grips.

When the concrete has reached the required strength to counteract the retracting force of the internal prestressing wires, it is good practice to gradually release the tension before cutting the element to size. This minimises the risks of concrete cracking if the tension were to be suddenly released whilst cutting when the whole of the element along the bed was still under tension. However this advice is at the discretion of the customer and the degree of safety and efficiency desired.

---