Post-tensioned concrete is described as concrete reinforced with tendons on site to allow for more complex shapes.

• A. Concrete cured on-site without reinforcement
• B. Concrete reinforced with tendons on site to allow for more complex shapes
• C. Concrete poured into wood forms
• D. Concrete that is poured in one continuous pour

Answer: (B)

Post-tensioned concrete uses embedded steel tendons that are tensioned after the concrete has cured to put the member in compression. This prestressing counteracts tensile stresses from loads, allowing longer spans and more intricate shapes with thinner sections and controlled cracking. The tendons run through ducts inside the concrete and are anchored at the ends once tensioned, which is typically done on site during construction. This is why describing it as concrete reinforced with tendons on site to enable more complex shapes captures the essential idea.

The other statements miss the key feature: ordinary concrete without this post-tress reinforcement, or simply pouring into forms, or pouring in one continuous pour, don’t convey the prestressing and the resulting ability to achieve complex geometries with improved strength and crack control.