I still think concrete is better.
A functional climbing tool could be constructed out of strong enough cord made optimally sticky.
No, Concrete couldn't be fired through but weapons could be placed on the top.
Have seen too much strong steel, aged, deteriorating, rusting through etc.
I understand your concerns but I’ll stick with the decision of the commander in chief. You know The billionaire real estate developer. With decades of construction experience. Who made his decision after consulting with the military, the border patrol, the Dept. of homeland security as well as other engineers and construction experts.
PS what do they put in concrete to make it stronger and not break?
Steel.
https://www.popularmechanics.com/technology/a20088202/concrete-rebar-practical-engineering