A construction technique used to strengthen and reinforce concrete structures. It involves the use of high-strength steel tendons or cables that are tensioned after the concrete has hardened. This technique allows for greater flexibility in design and can provide significant advantages over conventionally reinforced concrete.
Both methods squeeze the concrete in compression so it spans farther and cracks less. Pretensioning uses straight strands in a precast plant; post-tensioning threads a draped tendon and stresses it on site after the pour.