The purpose of post-tensioning is to strengthen concrete by actively pre-compressing it, thereby improving its performance under loads. After the concrete cures, tensioned steel cables (tendons) are used to put the concrete into compression, which significantly increases its load-bearing capacity and crack resistance. In essence, post-tensioning keeps the concrete in compression during service, counteracting tensile forces so the structure can support larger spans and heavier loads without cracking. This technique greatly enhances the durability and structural efficiency of concrete elements.

Key Points

• Actively pre-compresses concrete so service loads cause little or no tension cracking.
• Allows longer spans, thinner slabs, and fewer columns without sacrificing strength.