Yes this is very academic. In defense of prestressed concrete, I would like to say the only failures I have seen are when the loads are underestimated (a fault of the engineer, not the material), or, when the material is improperly used (improper concrete mix or defective, rusted steel). Or at worse both!
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The foam type forms are nothing more than a geeky curiosity, not a lot of real strength. The foam will break down with time. Also probably not much for blast or bullet resistance.
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Aside from bad materials or bad design, I saw a large prestresses bridge beam fail from improper handling at the plant. It literally exploded because of the tension in the stressing tendons. There can be 10s of thousands of pounds tension on each tendon. I'm afraid the same thing would happen if you lit off a big charge next to a prestress panel. The same panel with rebar instead may shatter the concrete, but without the tension of the stessing tendons it has a better chance of staying together, especially if you spray on heavy layers of elastomeric coatings.
As for ICF being a geeky curiosity, were still talking about 8"+ concrete sandwitched in between 2 layers of foam insulation with some sort of exterior siding. The siding and foam will offer some blast wave cushioning. The concrete is still concrete. Put in whatever steel you want (#4 @ 12" OCEW), use a hot 7000 psi mix and you will have a concrete wall.
How much of a blast will it take?
Will it stop a 50 bmg?
Does anyone else really care?
I don't know. You can run the numbers.
sq