What is a post-tension slab?

A post-tension slab is defined by the inclusion of steel cables that are tensioned after the concrete has been poured and partially cured. This process involves placing high-strength steel tendons within ducts in the concrete slab. Once the concrete reaches a specified strength, the tendons are tensioned and anchored against the concrete, which compresses the slab. This compression helps the slab handle tension forces, making it more resistant to cracking and bending under loads.

Post-tensioning is particularly useful in construction because it allows for longer spans without the need for additional support, leading to less cracking and deflection compared to traditional reinforced concrete slabs. The use of steel cables thus provides enhanced structural integrity and performance in various conditions, especially in areas prone to heavy loads or seismic activity.

In contrast, other options describe slabs that lack the essential reinforcement necessary for the improved strength and durability offered by post-tensioning. A slab without metal reinforcement or one that has only wood framing does not possess the tensioning benefits that are crucial to a post-tension slab's performance.