A: Poured concrete walls are actually structural beams. To help you visualize this, think about the horizontal steel I-beams you see as a skyscraper is being built.

For years, President Trump said he would build a wall out of concrete on the southern border. Now, he says it will be made of steel, not concrete. (Video: JM Rieger/The Washington Post) ...

Trump's "great wall" was a big concrete symbol of that. Except that now it isn't even concrete. In recent weeks, he has been saying it will be made of "beautiful" steel slats.

The former real estate mogul went from an original vision of precast concrete slabs — like those used “for parking garages,” Trump told a campaign crowd in August 2015 — to a “digital ...

Since then, his idea has shifted from a 1,000-mile, solid concrete wall, to a few hundred miles of "steel slats." Here's a look back at how the president's concept of a wall has evolved many times ...

Fiber concrete reinforcement can be a cost-effective, durable and even sustainable alternative to conventional steel like rebar and wire mesh. Can synthetic fibers compete “head-to-head” with ...