Concrete Shrinkage + Restraints = Tensile Stresses = Wall Cracks Another way of thinking about this shrinkage and restraint behavior is to place our 100 ft. wall in outer space.

Durability. A concrete wall can stand up to the test of time, often lasting for a century or longer. Resistance. Do you want a retaining wall that’s fireproof, rot-proof, and rustproof?

It’s a wall. You just misreported it. We’re going to build a wall.” Sources tell CNN Trump’s vision of a concrete wall is unrealistic, because of cost, timing, and safety.

The original block layers may not have the wall perfectly plumb or in the same plane, and one giant U-shaped form may be very hard to align if it’s one piece about 7 feet tall.