Project Description
Our story
On February 6th, 2023, a devastating earthquake struck Turkey and Syria. This was then followed by a series of earthquakes that destroyed the surrounding buildings. There were over 1.9 million people who lost their homes and over 850,000 Turkish/Syrian children displaced by the accident. Temporary shelters are being set up but aftershocks continue to plague the country. The combined death toll is over 500,000 in both countries (BBC, 2020).
Meanwhile, the cleanup work has also been a huge headache. Estimations show around 116-210 million tons of rubble need to be cleaned first. The UN is trying to encourage recycling of these materials but with all the chaos, most of it isn’t being disposed of properly. And even if the streets are successfully cleaned up, the rebuilding will also require gargantuan efforts. In Syria alone, more than 500,000 new buildings are needed to house everyone displaced (UN, 2023).
Retrieved from BBC article:
Far away, in Beijing, a group of students heard about the news many days later. The disaster shocked them. They wanted to do anything possible to contribute to the disaster, so they started brainstorming about projects to help clean up the damage. They wanted to help rebuild that community.
So, they started digging into the problem. And as they started diving deeper into the world of building materials, they realized two issues.
The Problem
The greatest issue with rebuilding the houses is concrete.
Concrete is everywhere. It is essential for almost every aspect of our life and is the most commonly used building material. Without this durable and versatile material, we would have never been able to build sleek modern cities filled with skyscrapers and smoothed out roads. However, concrete production accounts for 8% of the world's carbon emission, releasing 4 billion tons of carbon dioxide each year. The reason for such is its primary component, cement. The production process of cement emits sulfur dioxide, nitrogen oxide, and carbon monoxide. In addition, a ton of cement is made when it undergoes a 1400 °C burning process (the kiln, see below), which creates carbon dioxide from the energy used to fire the material (Princeton, 2020). To rebuild Syria and Turkey, carbon emissions seem almost unavoidable and concrete will definitely be used.
Retrieved Image from Research Gate article
Carbon dioxide is a greenhouse gas which means it is a gas that absorbs and radiates heat. It absorbs the heat radiating back from the earth’s surface and re-releases it back to earth. Increased carbon dioxide emissions are one of the greatest factors for the global warming effect which is impacting the world on a large scale. According to observations by the NOAA Global Monitoring Lab, in 2021, carbon dioxide alone was responsible for about 2/3 of the total influence of all greenhouse gases. Global warming then causes disasters all around the world like unpredictable weather, mass extinction evens, ocean pH changing, and ocean levels rising (Lindsey, 2023).
Global warming affects all of humanity but CO2 emissions is also a local problem for China. According to research conducted by Rhodium Group in 2019, says China emitted 27% of all greenhouse gases in 2019. This was almost over all the developed nations’ carbon emissions combined (BBC, 2021). This has caused terrible air pollution for all of China. Smog is common and in Team Keystone’s home city, Beijing, the AQI levels have an average of 60 with the AQI occasionally reaching levels of 300+ (extremely dangerous levels that warns of emergency conditions) (AQI, 2023). This is partly because of all the manufacturing done in factories (including cement ones) in Hebei, a nearby province. We hope to decrease this pollution and bring clean air to our home again.
And this isn’t all. A second issue that we learned is that concrete is extremely difficult to repair or recycle. Concrete can crack easily when first hardening. This is often because of environmental pressures like the temperature or the wind. After it cracks, it must be repaired immediately, or structural stability will be compromised. In some cases, repairing a small hole in a concrete driveway can cost as much as 150 dollars. This is extremely expensive and, in most cases, it would be easier simply to replace a section of the concrete (Fixr, 2008). Meanwhile, concrete can’t really be recycled either. The common method for recycling concrete is by crushing up old concrete to use as aggregates for new concrete. However, recycled concrete often has low strength and has a long project duration. It also doesn’t solve the problem of new cement being produced which will continue to emit carbon dioxide into the atmosphere (Construction How, 2011).
Given the two issues with traditional concrete, that is, being environmentally unfriendly and difficult to repair or recycle, it can be seen that reconstruction of cities after a devastating natural disaster like the Turkish-Syrian earthquake will require tremendous input of resources while being inefficient. In the aftermath of these natural disasters, tremendous amount of concrete will have to be produced directly from raw materials extracted from the Earth since recycling of destroyed concrete is ineffective as described above. The result of this is a large amount of carbon dioxide emissions produced from concrete production and being released into the atmosphere, leading to negative consequences in the long-term. The unfavorability of traditional concrete makes us interested in the possibility of having an innovative material that is more environmentally friendly and more favarable for repairation.
| On a scale of 1-5, how much do you know about the effect contrete have on the environment. (1 being left) | ||
| Options | Percentage of votes | Number of responses |
| Options | Percentage of votes | Number of responses |
| 1 | 25.80% | 8 |
| 2 | 29.00% | 9 |
| 3 | 32.30% | 10 |
| 4 | 6.50% | 2 |
| 5 | 6.50% | 2 |
| Total number of response: 31 |
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Yet with all the severity of this problem, according to our survey, 89% of people still show little or no understanding of the environmental impacts concrete creates. This is why it is essential to inform the general public about the sustainability problems with concrete production and find a new solution as soon as possible. We will accomplish this through our sustainability sector which we will combine with public education.
Our Project
In our project，we wanted to create a building material using clean technology that wouldn’t cause any pollution. We also hoped for it to be able to recycle old used materials. This way, it could be implemented in places like Syria where it could build new buildings out of the ruins of old ones––it would solve the problem of cleaning up rubble and building new houses in one go.
We were also inspired by stories about self healing buildings: we are dedicated to creating a Living Building Material (LBM) which will be composed of a sand-hydrogel matrix and
This will help us in our efforts to decrease the amounts of carbon emissions in the atmosphere. We hope to join in the effort of accomplishing the goal set by the UN and the Paris Agreement. We hope to help achieve a decrease of 7.6% emissions every year and by eliminating that 8% caused by concrete emissions, we will make it (Hohne, 2022). The fact that the net zero of CO2 in the atmosphere will also be decreased makes our project even more beneficial since it can slow down and even potentially reverse the trend of global warming through enough time.
By sequestering the atmospheric carbon dioxide, we will be able to produce calcium carbonate within the hydrogel matrix, through the precipitation by the cyanobacteria’s carbonic anhydrase. Specifically, this enzyme will convert carbon dioxide to hydrogen carbonate and a hydrogen ion. The hydrogen carbonate will further decompose into carbonate and hydrogen ion. When calcium ion is artificially supplied in the hydrogel, it will react with carbonate and form calcium carbonate, which is able to fill up the empty spaces within the hydrogel, creating a high density and low porous surface that is able to withstand high levels of pressure––just like traditional concrete.
Engineering
To enhance the efficiency and strength of carbonic anhydrase in engineered
1. Display carbonic anhydrase directly on the surface of cyanobacteria by connecting it to SLP (surface layer protein)
2. Display a SpyTag on the SLP of cyanobacteria and connect it to a SpyCatcher joined with CA (produced by E.Coli and purified)
3. Display a SpyTag on the piliA1 protein on cyanobacteria and connect it to a SpyCatcher joined with CA (produced by E.Coli and purified)
After completing the genetic engineering needed for our project, we mixed the engineered cyanobacteria with a matrix of hydrogel, sand (an example of an aggregate that could be considered, this could be later replaced with recycled concrete), and calcium ions, to obtain the end-product, which is a self-healing Biobrick, functional in both the form of a sealant and a brick.
Closing the Loop
In the end, after completing our project, we will then bring it out for public education and to gain the views of the masses on our product. By then, we will have helped educate groups on sustainability.
If our project is successful, then we will be able to end up using this one day in areas like disaster relief. We will be able to repair buildings in communities shaken by earthquakes at low cost and avoid pollution to the environment.
Goal
Our ultimate aim is to design an effective bioconcrete product that substitutes traditional concrete without compromising structural intensity. We will create a new sustainable “biostone” for the world that constructs a better shared future.
Project Diagram
References
Imbabi, Mohammed & Carrigan, Collette & Mckenna, Sean. (2012). Trends and developments in green cement and concrete technology. International Journal of Sustainable Built Environment. 1. 194–216. 10.1016/j.ijsbe.2013.05.001.
Princeton. (2020, November 3). CEMENT AND CONCRETE: THE ENVIRONMENTAL IMPACT. Retrieved October 11, 2023, from https://psci.princeton.edu/tips/2020/11/3/ cement-and-concrete-the-environmental-impact
Construction How. (2023, July 16). Recycled Concrete: Uses, Advantages and Limitations. Retrieved October 11, 2023, from https://constructionhow.com/recycled-concrete/
Fixr. (2022, August 19). How much does it cost to repair concrete driveway? Retrieved October 11, 2023, from https://www.fixr.com/costs/ concrete-driveway-repair
BBC. (2023, February 6). Turkey earthquake: Where did it hit and why was it so deadly? BBC. Retrieved October 11, 2023, from https://www.bbc.com/news/ science-environment-64540696
UN. (2023, March 6). More than 850,000 Syrian, Turkish children displaced by earthquakes. UN News. Retrieved October 11, 2023, from https://news.un.org/en/story/2023/03/1134182
UN. (2022, October 27). Emissions Gap Report 2022. UNEP. Retrieved October 11, 2023, from https://www.unep.org/resources/emissions-gap-report-2022
Lindsey, R. (2023, May 12). Climate Change: Atmospheric Carbon Dioxide. Climate. Retrieved October 11, 2023, from https://www.climate.gov/news-features/ understanding-climate/ climate-change-atmospheric-carbon-dioxide#:~:text=Without%20carbon%20dioxide%2C%2 0Earth's%20natural,causing%20global%20temperature%20to%20rise
BBC. (2021, May 7). Report: China emissions exceed all developed nations combined. BBC. Retrieved October 11, 2023, from https://www.bbc.com/ news/world-asia-57018837
AQI in China. (n.d.). AQI. https://www.aqi.in/us/dashboard/china