/diy/ - Do It Yourself

>>1828119
Since this is wrong on every point, let's go through it.

>That's normal for concrete after it's a couple years old
Not for any formulation of concrete ever used. Crumbling like that would interfere with any purpose for which concrete would be used. Imagine what would happen if a dam used "concrete" like that.

>it covalently bonds with trace minerals in the mixture and loses a little rigidity.
Concrete hardens and becomes rigid by a non-covalent hydration reaction between water and calcium silicates, both of which are major ingredients. This reaction continues for years, though it gets slower over time. On long time scales, concrete absorbs carbon dioxide from the air, which turns some of the hydrated cement into calcium carbonate, essentially reversing the process of cement production. This makes the concrete harder and tougher, not more brittle.

>As long as the beams
Beams are horizontal structural members. The things in the video are columns.

>were installed correctly
They were cast in place, not "installed", and they were obviously cast incorrectly. What with all the loose aggregate.

>it literally can't cause any problems
Those are load-bearing columns. Such things are overengineered, so it may not collapse immediately. That's not out of the question with such poor bonding, however, and in any case the robustness to handle things like storms or earthquakes will be severely reduced.