Then they were falling, and the view ahead was filled with concrete.

But the Dutch did not have the required experience yet using and building with concrete.

Most of the ground area had been paved with concrete.

Even if they covered over the whole planet with concrete, one day it would just happen.

Windows on the ground floor were filled with concrete during the 1950s as well.

These were set into position and then filled with concrete.

I'm thinking about my area, where everything is paved with concrete.

To do it the modern way, you would definitely go with concrete.

It was a metal door, faced on the outside with concrete.

Could we not reach the same end with asphalt or concrete?