Concrete has turned out to be the essential building material for nearly almost everything, but mostly, the vital points such as dams, bridges, and massive accommodation.
But, at the same time, it has one of the largest footprints of carbon emission during production. Researchers now experiment with root vegetables and recycled plastic in concrete for stronger structure probability. And the second question is sustainability, even to power streetlights or air pollution sensors.
Concrete is the second most widely-used substance in the world following water. Cement production is responsible for about 8% of global carbon dioxide (CO2) emissions. Burning many minerals, shells, shale, and other components in kilns, where fossil fuels are used, heated to about 1,400°C, eventually produces CO2 emissions.
In addition, clinker yields a high-temperature chemical reaction, and the reaction is energy-intensive.
When cement is mixed with water, it forms a paste that binds together aggregates and thus allows concrete to harden and gives strength and structure.
Making cement stronger is one of the most essential topics not only for structures’ strength but also for decreasing the environmental effects. Professor Mohamed Saafi from Lancaster University in the UK and his colleagues target to achieve this as part of the B-SMART project.
Cement and water combination is necessary so adherence with sand and crushed rock occurs. However, all cement particles do not get hydrated. Prof. Saafi says “Most of them remain essentially sitting there doing nothing which is a waste. “If we can amplify this hydration mechanism, its strength will increase significantly, and therefore we can use less cement.”
Prof. Saafi and his team found root vegetables as a solution. They researched that if carrot waste material from baby food production or beet sugar remains could be added to cement for strength. By using computer simulations, it was possible to see the super-thin vegetable sheets thrown into the cement paste would interact with cement, observed their effect on both the hydration of cement and resulting mechanical properties. Then they conducted experiments in the laboratory for the confirmation of simulations.
The researchers found that incorporating sheets were able to enhance cement hydration. The sheets acted as reservoirs allowing water to contact more cement particles and thus improve its binding ability. “At the same time, once the hydration is over some of these carrot nanosheets remain in the cement and make its structure very strong,” states Prof. Saafi. “We haven’t seen this before and it’s really an amazing discovery.”
The researchers are now completing field tests to see if structure elements simulated in the laboratory can be implemented in real-life conditions. They also target using existing processes during the production of their new concrete method to help decrease costs.
If all stages are completed and the process provides the same properties in real conditions, the team expects their vegetable cement could reduce the necessary amount of cement for building structure by 10 kg per cubic meter of concrete.