Pretensioning

Definition

Pretensioning is a method by which the design tensile force is applied to the steel reinforcing before the concrete is set.

Purpose

Pretensioning improves the structural capacity and durability of concrete elements by preloading the steel reinforcement, which counteracts the tensile forces that occur in service.

Examples of Use

• Precast Beams: Manufactured with pretensioned tendons for enhanced strength.
• Concrete Slabs: Pretensioned slabs provide increased load capacity and span lengths.
• Structural Panels: Used in wall and floor panels to improve performance and reduce cracking.

Related Terms

• Post-Tensioning: A similar method where the tendons are tensioned after the concrete has set.
• Prestressed Concrete: Concrete with internal stresses introduced through pretensioning or post-tensioning.
• Reinforced Concrete: Concrete that includes steel reinforcement for added tensile strength.

Notes

• Process: Involves stretching the steel tendons before pouring the concrete, then releasing the tension once the concrete has cured.
• Applications: Commonly used in precast concrete manufacturing for elements that require high tensile strength.