Post-Tensioning

Definition

Post-tensioning is a method by which concrete is compressed after it has been cast by stressing the steel reinforcing. This involves compressing the concrete in a structural member by means of tensioning high-strength steel tendons against it after the concrete has cured.

Purpose

Post-tensioning enhances the strength and performance of concrete structures, allowing them to bear greater loads and span longer distances without cracking or deflection. It is commonly used in bridges, slabs, and high-rise buildings.

Examples of Use

• Bridges: Strengthening bridge decks to support heavy traffic loads.
• Concrete Slabs: Reducing the thickness of slabs while maintaining structural integrity in parking structures and residential floors.
• High-Rise Buildings: Increasing the load-bearing capacity of floor slabs in tall buildings.

Related Terms

• Pre-Tensioning: A method where tendons are tensioned before the concrete is cast.
• Reinforced Concrete: Concrete that contains embedded steel reinforcement to improve its tensile strength.
• Tendon: A high-strength steel cable used in post-tensioning.

Notes

• Process: Involves placing tendons in ducts within the concrete, tensioning them after the concrete has cured, and then anchoring them at the ends.
• Advantages: Provides greater flexibility in design, reduces material usage, and enhances durability.