Commercial buildings benefit from the use of concrete in their construction take off service. Concrete is a durable material that can withstand wear and tear. It can also support heavy equipment and machinery. These factors makes it a great material for flooring and foundations for commercial buildings. One method that is common for concrete structures is post-tension concrete. This method utilizes the strength of concrete and steel in combination with pre-stressing the concrete and post-tensioning the steel. If you’re looking to create a surface that is extra durable for a large commercial building, here is the best practice for installing post-tension concrete.
What is Post-Tension Concrete?
Before we get into the best ways to install post-tension concrete, it’s important to understand some of the science behind post-tension commercial concrete. Post-tension concrete utilizes both concrete and steel at their strongest. Concrete is at its strongest when it’s under compression. Whereas steel is at its strongest when it’s under tension. When you use both of these materials in their strongest states, you end up with an incredibly strong concrete slab to build on.
Post-tension concrete is a bit different from just using rebar to reinforce the concrete slab. Rebar can help strengthen concrete, but adding tension also strengthens the steel. Post-tension concrete has become a popular method in construction for commercial buildings that need to support a lot of weight. You’ll most commonly see post-tension concrete in parking garages and large modern commercial building projects.
Materials for Installing Post-Tension Concrete
Post-tension concrete requires more materials than pouring normal concrete with just rebar. When looking for the best practices for installing post-tension concrete, you will need the following materials.
- Post-tension cables AKA Tendons
- Ducts of Tubes
- Anchors
The post-tension cables are made from a braided steel cable. The tendons need to be protected from water when the concrete is poured, so you’ll need to place them inside a tube or duct. This prevents the cables from interacting with water and becoming damaged. The anchors will apply force to the tendons and keep that force in place. You’ll then use a hydraulic jack once the concrete is cured to add stress to the tendons.
Best Practices for Pouring Post-Tension Concrete
The key to creating a good post-tension concrete slab is to make sure you don’t pour concrete into the tendons. The tendons will be installed so that they’ll be protected from bonding with the concrete. You’ll work with the steel by placing it flush along the rebar in the concrete formwork.
Once the tendons are placed alongside the rebar, you can carefully pour the concrete being mindful to not get any into the tubing. You’ll also need to make sure that all of the tubing is in the correct spacing during the pour and doesn’t move. This ensures that you are creating the strongest framework for your concrete.
You’ll then wait until the concrete is cured up to 75% before starting the stressing process. This curing time can take around 23 days before it is complete. At this time, you’ll use a hydraulic jack to stress the tendons. Then, you’ll have a durable concrete slab.
Why Post-Tension Concrete?
Post-tension concrete not only creates a concrete slab that’s more durable than a normal slab. It also gives the architects in the project more freedom in their design. Post-tension concrete allows for the use of thinner concrete slabs and fewer support columns. This gives designers the freedom to open up floor plans and get creative with the design of a commercial building.
Post-tension concrete is less susceptible to cracks and damage over time. Since you are creating a stronger concrete slab, it is less likely that the concrete will endure bad damage for a very long time. You can save money on repairs and have peace of mind that the construction will be safe over time.
Post-tension concrete allows you to use less rebar in favor of tendons. Tendons tend to be a cheaper material than rebars. Since you are adding strength to the concrete, you also don’t have to pour as much concrete as you would with other methods. Many construction projects tend to save a lot of money on materials and labor costs when opting for post-tension concrete.
Post-tension concrete is also one of the faster concrete construction methods. It can help speed up the construction process for the building and in turn, save money in the long run.
Conclusion
Post-tension concrete has become an incredibly important method in modern construction. It allows for creative freedom for designers. And it also ensures that the material you are making is strong and will last for years to come. Construction sites and project managers should work with concrete professionals and follow the best practices to have the best results with their post-tension concrete.
