Translucent concrete lets the light shine through

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.

Called 'Liquid Stone,' the show features variations of translucent concrete, a newfangled version of the old construction stand-by that offers a combination of aesthetics and practicality.

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

'I think it's beautiful in itself, so it might be attractive in a restaurant or a hotel,' said G Martin Moeller Jr, the museum's senior vice president. 'But it might also be used in an indoor fire escape where you wanted light to come through in case of a power failure. It could become a lifesaver.'

The translucent blocks are made by mixing glass fibres 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 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 to do post-graduate work in architecture and it developed there,' Losonczi said.