Introduction to Prestressed Concrete

Introduction to Prestressed Concrete

Prestressed concrete involves applying an initial compressive stress to concrete to counteract tensile stresses caused by service loads.

Methods of Prestressing

1. Pre-tensioning: Tendons are tensioned before concrete is cast. Common in precast plants.
2. Post-tensioning: Tendons are tensioned after concrete has hardened. Ducts are cast into the concrete.

Stages of Loading

1. Transfer: Immediately after prestressing force is transferred to concrete. Concrete strength is $f'_{ci}$.
2. Service: After all losses have occurred and service loads are applied. Concrete strength is $f'_c$.

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