Post–tensioning is a method of reinforcing concrete in a slab and beam. Post-tensioning is a form of prestressing.In post tension slab tendons are prestressing steel wires inside plastic ducts or sleeves or metallic sheets and it is positioned in the forms before the concrete is placed.

After this process concrete gets strength but before the service loads are applied the cables are tensioned and anchored against the external edges of the concrete slab.

What Is Post Tension Slab?
Post tension slab is a combination of conventional slab reinforcement and extra projecting high-strength steel tendons which are continually subjected to tension after the concrete has been settled down.

This method helps to achieve the formation of a thinner slab with a longer side span devoid of any column-free spaces.