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.

Exposed concrete features prominently inside, including its floors and walls, while white also plays a prevalent part in the design. A stark white office contrasts strongly with the neighbouring ...

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.