There are two methods of Pre-Stressing
Post-Tensioning is a method of reinforcing structural elements. Concrete is weak in tension and strong in compression. Compressive stresses are induced in the concrete section by pre-tensioning or post tensioning. The ‘pre’ in pre-tensioning refers to introduction of stress before any application of loads. The ‘post’ in post tensioning refers to tensioning of strands after the casted concrete has achieved sufficient strength.