See through concrete

It used to be only Superman who could see through concrete walls, but an exhibit at the National Building Museum shows mere mortals can do it, too.

The show, "Liquid Stone," features variations of translucent concrete, a newfangled version of the construction standby that offers a combination of aesthetics and practicality.

One display is a wall of translucent concrete blocks. When someone stands in front of the wall and light is shone from behind, the person's shadow can be seen clearly on the other side.

The translucent blocks are made by mixing glass fibers into the combination of crushed stone, cement and water, varying a process that has been used for centuries to produce a versatile building material. The new process was devised by Hungarian architect Aron Losonczi in 2001.

"The idea came from a work of art I saw in Budapest," he said in a telephone interview from Csongrad in southeast Hungary. "It was made of glass and ordinary concrete, and the idea of combining the two struck me. Then I went to Stockholm [Sweden] to do postgraduate work in architecture, and it developed there."

Exhibit casts concrete in a whole new light