Thursday, January 23, 2020

Concrete That Can Reproduce

A new type of concrete is under development -- a concrete that is said to be "alive." Not alive in the usual sense, but alive in that it is able to reproduce.

This concrete is being researched at the University of Colorado, Boulder by an interdisciplinary team using cyanobacteria, microbes that use photosynthesis to capture energy and use that energy to absorb carbon dioxide from the air, turning the sand in the mix into calcium carbonate, or cement. The trial mixture is water, sand, nutrients, cyanobacteria and gelatin (which seems to help the matrix built by the bacteria).

Experimental blocks reached maximum strength over a few days, but even after several weeks they were still alive and were able to spawn new blocks when put in molds with new ingredients. The potential advantage of this system is that it does not use Portland cement, and is not fussy about the type of sand it uses: it could even be recycled glass or recycled concrete. There are really positive environmental implications.

Funding for the project was through Darpa, the US Department of Defense's speculative research arm.