Specifications: Post-Tension Concrete Cables
Post-tension cables are steel, flexible cables made from several strands of steel wire intertwined with each other in order to form a thicker steel “wire” which we call the Post-Tension cable. The name “Post-Tension” comes from the fact that this cable is stressed with tension forces, after (“post”) a concrete structure has been poured, and has cured for a few days (exact wait time to begin to tension the cables depends on the concrete structures’ specs).
The way Post-Tension cables are installed is as follows.
Lets use a foundation slab as an example if a use case for post-tension cables. First we grade and apply proper sub-grades to the surface where the slab will be built on. Then we form the area where the slab will be poured (“pouring” is the process of laying down the wet ready-mix concrete inside the concrete forms). Next, since we want this slab to be extra strong, we use a type of concrete reinforcement called post-tension concrete, instead of the traditional rebar concrete reinforcement.
Post-tension cables are therefore the next part of the foundation concrete slab that are installed. Post-tension cables are installed by trained and specialized individuals who are certified to install post-tension cables, usually working for a decently “large” company. The post-tension cables are put down on the inside of the concrete formed-area. Each cable is put down from one end of the slab across to the opposite side. The tips of the cables are attached to the forms on each side with special lock-mechanisms. Cables are usually put down on two different directions of the slab, for example some cables running from North-to-South, and other from West-to-East.
That’s a short explanation of how Post-Tension cables are installed and what they are. Below are some specs about the post-tension cables that we use for our sport courts: