What type of concrete structural system utilizes post-tensioning to enhance strength after the concrete has cured?

The type of concrete structural system that utilizes post-tensioning is post-tensioned concrete. This method incorporates high-strength steel tendons within the concrete before it is poured. After the concrete has cured, these tendons are tensioned and anchored to the concrete, which induces compression within the concrete itself. This compression increases the overall load-carrying capacity of the structural element and minimizes potential cracking, especially under tensile loads.

Post-tensioning allows for longer spans, thinner slabs, and more efficient use of concrete material, making it a popular choice for commercial and industrial structures. The process helps to control deflections and can be particularly beneficial in structures subjected to varying loads or environmental conditions.

While reinforced concrete and precast concrete are also effective in providing structural strength, they do not involve the post-tensioning technique. Reinforced concrete relies on the use of steel rebar to handle tensile forces, and precast concrete elements are manufactured off-site and then brought to the construction location, where they are typically precast with varying properties rather than post-tensioned on-site. Composite construction refers to the combination of different materials to create a structural solution, which does not specifically involve post-tensioning in the context described.