Summary/Summary Reader Response Draft #1: Concrete that grows

The article “Scientists create living concrete from bacteria and sand” by Corless, V. (2020) introduces the usage of bacteria in concrete mixes to make concrete. Many possible methods are being explored by researchers but no results cater to cement’s desirable properties. The articles mentioned that "Researchers from University of Colorado Boulder mixed sand, a hydrogel, and bacteria to create a living substance with the strength of cement-based mortar and the prospect to perform photosynthesis." "The researchers used a 3D sand–hydrogel scaffold that contains Cyanobacteria. Cyanobacteria are able to survive in extreme environmental conditions. It also can convert CO2 to sugars during photosynthesis. These materials are able to be replicated by a parent “brick”. The bricks are still able to perform the same biological functions as the parent brick by separating and extending with hydrogel scaffold." explained by Corless. The author discussed that a bacterium can do much more than previous findings of being to help the concrete to heal its own cracks.There are many reasons why ‘living concrete’ is the future in the construction industry with the many benefits it has. 

One of the reasons is that it adds nutrients to the concrete that enable it to sustain longer as compared to normal concrete, this value adds to the concrete. Synechococcus is a kind of bacterium that is utilized in living concrete. This bacterium meets the Cyanobacteria requirements. It obtains energy through the photosynthesis process. In the presence of chlorophyll, it absorbs carbon dioxide, sunlight, and certain other nutrients and releases calcium carbonate and oxygen.

Another reason is that ‘living concrete’ constitutes better properties than ‘non-living concrete’. There has been a lot of biological study on the perimeter of structural concrete. This has largely taken a lot of study attempting to find out how live organisms' shells gain some of their astonishing features. However, it has also featured the notion that living creatures may build structural carbonates, as well as a few efforts to create concrete that self-heals due to the presence of carbonate-producing microbes embedded in it."

However, one disadvantage will be that concrete contains gelatine. Even though this was sufficient to sustain basic structures for long enough for the cyanobacteria to begin building carbonates. The cyanobacteria, on the other hand, simply do not make enough carbonate in a week to give the "concrete" the material toughness we associate with true concrete. To do better, the entire thing must be dried out, in order to eliminate the bacteria in the process.

To sustain the bacteria in the brick, there is a trade-off of the cement’s strength. Bacteria can function in the moist, but the mixture is stronger when it's dried. Currently, this technology is still new. It only can be represented as a possible alternative to cement in construction.

References

Corless, V. (2020, January 20). Scientists create living concrete from bacteria and sand. Advanced Science News. https://www.advancedsciencenews.com/scientists-create-living-concrete-from-bacteria-and-sand/

Timmer, J. (2020, January 18). “Living concrete” is an interesting first step. Ars Technica. https://arstechnica.com/science/2020/01/living-concrete-is-an-interesting-first-step/

Living Concrete: Advantages and Problems. (2020, April 19). The Constructor. https://theconstructor.org/concrete/living-concrete-advantages-and-problems-pdf/37822/