Wednesday, August 30, 2006
Builder bacteria
Newer materials that promise to revolutionise construction practices are taking shape in laboratories. "We will soon be using basalt rock and even bacteria to come up with stronger and eco-friendly structures," says Prof. Dr. V. Ramakrishnan of South Dakota School of Mines and Technology, U.S.
On new construction material that are in the making:
There are four that could be described as future construction material. Three of these are in laboratory stage and will be available in the coming years. It includes 3D reinforced concrete and reinforcing rods made from basalt, bacterial concrete and geo-polymer concrete. The fourth is fibre-reinforced concrete, which has fibre replacing steel, and is being put to extensive use in U.S. and some other countries.
On use of bacteria in construction: `Bacillus pasteurii' could be the answer to the long quest for a crack-free concrete. This one does not die and provided the right food (medium), fills micro-cracks and makes it impermeable. Our findings have been repeated by others and proved to be quite effective.
On basalt replacing steel: Most structures fail due to steel corrosion. A building can be stronger if you get a material that does not corrode. We took basalt rock, melted it down to make fibre which does the required job. We proved that basalt rods could be used in reinforced concrete. In 15 to 20 years, this will come into practice.
On geopolymers as a substitute for cement: Geopolymer concrete uses fly ash, which is a waste material, and does away with cement. This new concrete is not only environmentally safe but also ensures more strength.
