Summary/Reader Response Draft 1: Concrete That Grows (b)

According to the article, written by Corless, "Scientists create living concrete from bacteria and sand", researchers from the University of Colorado Boulder have created living concrete from bacteria and sand. They have introduced a new living material, by combining sand, hydrogel and bacteria.

The article explains that photosynthetic cyanobacterium was biomineralized with a 3D sand-hydrogel scaffold, which produces new bricks from the original brick. The article also claims that biological viability and mechanical performance cannot coincide. Thus, additives are incorporated to enhance the quality of the material. Hence, it possesses properties that are comparable to cement-based mortar, which carries biological purposes. Corless interviewed Srubar (2020), the director of Living Materials Laboratory, he claimed that this process will change people's thinking about the manufacturing industry and reusable materials.

Corless further mentions that despite this technology being in its early development phase, it represents a new era in material manufacturing: a new grade of responsive materials “in which structural function is complemented by biological functions.”

In my opinion, due to technology’s rapid advancement, there are alternatives like turning fungi into 'bricks' for construction, using ground granulated blast furnace slag as a partial replacement for cement, and utilising 3D printing formwork for construction. These alternatives could perhaps enhance concrete or replace it in the near future.

Let’s delve deeper into the alternatives. You must be thinking, how could mushrooms be used as a building material for infrastructures and perhaps make a house from it? Aren’t mushrooms small and fragile organisms used for consumption purposes? However, in a news article, written by Begum, “Turning fungi into ‘bricks’ for construction”, researchers from the Nanyang Technological University (Singapore) and Swiss University ETH Zurich (Switzerland), have collaborated to create mushroom bricks from mycelium, a component in fungi. Their research purpose is to optimise growth of mycelium, while infusing it with 3D printing to build mycelium-based structures that could be used for construction. As these fungus grow on waste, mycelium secretes proteins which bind loose materials together to form a web. Naturally, the web forms into a mould, shaped as a block like a brick. These bricks are then heated to stop the growing process. The article explains that mycelium is organic and biodegradable, meaning it’s able to return to nature once its purpose has ended. Therefore, these building blocks not only serve well in the construction industry, they do not occupy landfills.

Moving on, let’s discuss GGBS. Originally, it is a byproduct from blast furnaces used to produce iron, and it comes in the form of slag from remaining materials. As a byproduct, we may think that it is a waste product that should go to the dump. But no, it can serve as an eco-friendly construction material after the slag has been through some curing process, and it gives us our GGBS. In a research article, produced by International Journal of Innovative Science and Research Technology, “Studies on Optimum Usage of GGBS in Concrete”, research scholars from the University of Pondicherry (India), have conducted a study on ground granulated blast furnace slag (GGBS) to incorporate it into concrete, and partially replacing cement with it. From their study, the test results concluded that replacement of GGBS in concrete can produce high strength comparable to conventional concrete mixes. The article stated, “The workability of the concrete increases with the increase in the GGBS content for M25 grade concrete and the workability reaches its maximum at 50% replacement of GGBS.” This proves that GGBS can replace cement without affecting concrete strength.  

Lastly, the use of foam for construction structures. Foam in general is an object that traps air, liquid and solid. It is known to be a soft material which comprises many disorientated bubbles of different sizes. Hence, it does not have a firm and fixed form. However, in an article, written by Hahn, “This innovation uses 3D printing to cut concrete use”, researchers at ETH Zurich, have used 3D-printed recyclable formwork elements to create a precast concrete slab called ‘FoamWork’. Their innovation allows reduction of CO2 emissions from material production in concrete and utilising waste products like fly ash from coal-fired power stations. By incorporating 3D printed recyclable formwork elements with fly ash, it helps to minimise the carbon footprint of their foam. Furthermore, the article states, “The final FoamWork elements can either be left in place to improve the insulation of the precast concrete slab or recycled and reprinted to create new formwork”. Therefore, this suggests that not only is FoamWork eco-friendly, it is sustainable and is able to cut down the usage of concrete.

However, despite looking into these alternatives, there are some still under development while  others are newly out in the construction industry. For instance, the use of GGBS to replace cement. Although GGBS can be comparable or could produce better results than cement, it poses issues like long production time due to it setting slower than cement and it takes a longer time to gain its desired strength. Therefore, this may affect construction schedules.

To conclude, in years to come, given the advancement of technology, I believe these eco-friendly alternatives can replace concrete and create a new age for the construction industry.

   

References:

Corless, V. (2020). Scientists create living concrete from bacteria and sand. Retrieved 30 January 2022, from https://www.advancedsciencenews.com/scientists-create-living-concrete-from-bacteria-and-sand/

Begum, S. (2021). Turning fungi into ‘bricks’ for construction. Retrieved 8 February 2022, from https://www.straitstimes.com/singapore/environment/turning-fungi-into-bricks-for-construction?close=true

International Journal of Innovative Science and Research Technology. (2017). Studies on Optimum Usage of GGBS in Concrete. Retrieved 9 February 2022, from https://ijisrt.com/wp-content/uploads/2017/06/STUDIES-ON-OPTIMUM-USAGE-OF-GGBS-IN-CONCRETE-UPDATED-MANUSCRIPT-.pdf

Hahn, J. (2022). This innovation uses 3D printing to cut concrete use. Retrieved 9 February 2022, from

https://www.weforum.org/agenda/2022/01/eth-zurich-3d-printer-concrete-carbon-emissions/