Pre-tensioning and Post-tensioning both methods are used under pre-stressing process which has few edges over the orthodox non-stressed structures like greater span to depth ratio, higher moment and shear capacity. These methods are generally adopted in the making of PSC girders, sleepers etc.
pre – tensioning
1- In this method the concrete is prestressed with tendons before it is placing in position.
2- This method is developed due to bonding between the concrete and steel tendons .
3- Pre tensioning is preferred when the structural element is small and easy to transported.
4- In this method similar prestressed members are prepared .
5- Pre-tensioning members are produced in mould.
post – tensioning
1- In this method prestressing is done after the concrete attains it’s strength
2- This method is developed due to bearing
3- Post tensioning is preferred when the structural element is heavy
4- In this method products are changed according to structure .
5- Cables are used in place of wires and jacks are used for stretching.
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