Bacteria to reinforce buildings

Natural soil bacteria could be used to stabilize buildings against earthquakes, turning loose sand around the building's foundations into sandstone, say researchers at University of California - Davis. Soils behave very differently during an earthquake, with sandy soils adopting characteristics more akin to a liquid, with disastrous consequences for any building that might be perched above. Currently, engineers can inject glue-like chemicals into the soil to bind loose grains together, but these epoxy chemicals could have toxic effects on the soil and may leech into groundwater. Jason DeJong, of UC Davis, explained that the new process uses Bacillus pasteurii, a natural soil bacterium that causes calcite (calcium carbonate) to be deposited around sand grains, cementing them together. In the laboratory, DeJong and his co-researchers found that with the addition of bacterial cultures, nutrients and oxygen, they could turn loose, liquefiable sand into a solid cylinder. "Starting from a sand pile, you turn it back into sandstone," DeJong said.

Source: scienceagogo.comAdded: 27 March 2007