Posted by Big Gav
CleanTechnica has a post on a new technique for building roads without using bitumen - Bacteria Can Build Better Roads for Our Peak Oil Years.
Local jurisdictions in Red state America, increasingly unable to agree to taxes to jointly afford repaving at peak oil prices are simply letting roads decline – in the same way as after the fall of the Roman Empire, in the dark ages there, many roads in Europe returned to mud tracks.
But an innovative new oil-free way of surfacing roads could be on the way to save us from peak oil. This “sandstone” road surface is built by bacteria just using sand, so it’s cheaper. The idea from Thomas Kosbau + Andrew Wetzler is the winning entry in the Korean green design iida awards, announced by designboom.
The idea is to use an abundant resource – sand – and to mix the sand with a solution containing the microbe Bacillus Pasteurii, which cements the sand into a biologically engineered hardened sandstone. Then the sand-and-microbe solution is sprayed onto a layer of sand underneath and hardens the whole thing into a tough road surface made of bio-sandstone.
Currently roads are built of asphalt – a toxic material made of crude oil, that creates heat islands and is subject to peak oil. The advantages of replacing asphalt are both financial and environmental.
It takes 320 barrels of oil to build one kilometer of asphalt roadway. Made from crude oil, asphalt had a price rise of 222% between 2003 and 2008, which is symptomatic of peak oil and likely to keep happening as we use up the remainder of a finite resource.
Asphalt off-gasses, especially in hot weather, and is carcinogenic, causes birth defects, and is harmful to skin and the immune system. Asphalt roads contribute to the heat island effect, reaching temperatures of up to 150 degrees, transferring the heat to air.
If their “sandstone” is strong, durable and long-lasting enough, this bio-engineered road would appear to be brilliant solution. Not only does it take less energy to light a light-colored road surface at night, but the reduction in the heat island effect alone could reduce city temperatures up to 3 degrees C, further lowering city needs for air conditioning, which in turn further reduces CO2 emissions.