Researchers from the Fraunhofer Institute for Building Physics have developed a method to break down old concrete debris into its constituents for better recycling and re-use of the material. The process, called electrodynamic fragmentation, uses very short pulses (less than 500 nanoseconds) of induced lightning to separate gravel from cement materials in concrete.
Concrete is a material with a mixed environmental pedigree. Although its workability and durability make it extremely useful for a lot of purposes, it also has several drawbacks. There are the environmental impacts from the production of concrete, and it is also a major component of the materials going into landfills, so this makes the idea of recycling concrete a compelling one.
At present, most concrete recycling is merely to crush it and use it for sub-base under roads. This is better than landfilling it, but is a downcycling of the material. With the new lightning process, the aggregates can be more readily salvaged and re-used in new concrete.
Production of new cement from the recovered, separated material would be the ultimate goal of concrete recycling, since the production of cement is one of the single most intensive sources of CO2 emissions at present. While this process does not accomplish that, it does lay the way for that kind of recycling to become a possibility.
written by Cathie of Reflective Tapes, December 12, 2012
written by Concrete Pumps, March 12, 2013