Why Pre-Stress Concrete?

Post tensioned concrete is why you never cut into a concrete slab without first KNOWING that it is not post-tensioned, or without having it scanned so you know where the rebar or post tension rods are. If you cut into one of the rods it can explode out of the slab and cut through anything in its path, finishes, furniture, or you.

I’m a mechanical engineer. I graduated with my degree in 1986. I’ve always been amazed at the things that civil engineers design. Bridges and buildings are built to last a very long time under very heavy loads. Thanks for a quick peek behind the scenes.

I worked on a project where we grouted the cables after post tensioning. The grouting reduced the risk that a cut cable or a cable's locking wedges slip and the cable launching itself horizontally from the end of the slab into the neighbour's property. 😮😊

Really enjoyed your presentation. As an ironworker I installed a lot of post tension cable on-site. Always thought it was interesting.

My dad was a civil engineer for Wells Concrete Products and I spent my college summers working as a laborer there. It always amazed me to see 60 or 70 foot double tees bend when the pre-stressed cables were cut loose from the form. The center would pop up 3 or 4 inches above the form. You look at concrete and think "That can't bend". Oh, yes it can!

I've only ever designed rebar reinforced concrete so this video was a great introduction into some pre and post tensioned design considerations.

Could you make a full 101 video on traditionally reinforced concrete? Really interesting overview of pre-stressing--thanks!

Informative, thank you 🤝

Great Video. As requested, future discussion on the cable stretching engineering theory, along with the the equipment and methods for stretching PT cable would be insightful to watch. Also a video about post tension cable repair would be useful to.

Interesting and easy to understand. Cheers.

railway sleepers are also made either with reinforced concrete (a simple steel bar mixed in concrete) or with prestressing (a steel bar stretched, during the drying time of the concrete.

Thanks, I used it for my Engineering students!

An educational video. Thanks for your time.

Thank you so much, The Subject was very helpful .

I'm also interested to see a video on floor diaphragms and how they interact with stair cores, shear walls. Anything to do with lateral forces in general 👍

Top content keep it up! A Video about Tunnels keeping dry and withstand sheering forces in the mountain would be Interesting.

You learn something everyday. Thanks

I heard that in some cases prebuilt pretension concrete stuff was actually cheaper since you could control the conditions and just build a bunch of them as needed

fortunate i found your video. thannks

If anyone wants to see the most incredible, INCREDIBLE example of pre-stressed concrete, look-up how they built the super-skinny CN Tower in Toronto way back in the 70s. The entire tripod bottom of the tower is basically three 1000' skinny pre-stressed beams. The combination of step-forming and running highly stressed cable throughout the construction process is still mind blowing all these years later. Then there's the fact that the entire 1800' tower is built on a foundation that is only 16' deep, sitting on bedrock.