Nov 1, 2010 08:49 GMT  ·  By
Asphalt can be replaced by a mixture of sand and microbes, which produces a tough road pavement material
   Asphalt can be replaced by a mixture of sand and microbes, which produces a tough road pavement material

Given that we are at, or nearly at, Peak Oil, it stands to reason that the costs associated with building roads are increasing, and that government can no longer afford to maintain their road systems. Now, a new method of producing asphalt is being developed to counter these effects.

The technique is critical for avoiding the fate of roads in the Roman Empire, which were left to decay into mud tracks once Rome did not have enough money to support their maintenance.

This is happening now more often than not, especially in developed countries that have been hard hit by soaring oil prices. Crude and derivate substance are necessary for producing asphalt.

In its natural state, asphalt can be found in most crude petroleums, but chemists are still having a rough time determining its individual components, and the role each of them plays in producing the properties this material is needed for.

As oil prices boom, the costs of paving roads using asphalts go up as well, but at even higher rates, due to added intermediaries that further refine the compound.

Now, scientists have produced a method of creating a biological substitute to asphalt, that could be produced at much lower costs, and have the same behavior as a paving material.

The new “sandstone” road surface is produced by using sand and a specific type of bacteria. The idea belongs to designers Thomas Kosbau and Andrew Wetzler, who are the winners of the Korean green design competition the iida awards.

The team says that mixing common sand – one of the most abundant resources on the planet – with a solution containing the microorganism Bacillus Pasteurii could result in a cementing process that turns the mix into biologically-engineered hardened sandstone.

After the two are mixed, the solution is sprayed on yet another layer of sand. The microbes act again, solidifying the layer underneath, and resulting in a tough, road-worthy material that can sustain heavy traffic.

Additionally, given the low cost of manufacturing the material, it will be a lot cheaper to repair it as well. When cracks appear, all maintenance crews will have to do is spray some of the bacteria solution within, and leave the road to solidify again.

Yet another advantage is that the method is very environmentally-friendly. One kilometer of asphalt road requires some 320 barrels of oil to complete, and this need could be eradicated altogether.

As a material, asphalt should not be the first choice when building roads, ever. It gives off harmful gases when subjected to high temperatures, and it also melts and deforms.

As a chemical, it has carcinogenic properties, and has been proven to causes birth defects, affect the skin and compromise the immune system, Clean Technica reports.

Details of the new proposal at designboom.