Concrete Tent–Just Add Water

This amazing bit of building technology was inspired from medical casts used to immobilize limbs.  This Concrete Canvas Shelter shows up packed flat in a waterproof plastic bag.  You simply fill the bag with water, soaking the concrete infused canvas, and then inflate to make a permanent structure.  This concrete tent hardens in about 24-hours and is then strong enough to stand on, is fireproof, waterproof, and possibly zombie-proof.

[Via]