
Revolutionary Construction Breakthrough Turns Debris Into Concrete
Concrete Block That Captures Carbon Dioxide
• • • • • • • September 25, 2024 • • • • • • •

There is a new invention by the researchers at the University of Tokyo. They have developed a revolutionary new kind of concrete. Professor Ippei Maruyama led the development of this product at the university. This new concrete removes many of the wasteful steps commonly used in producing concrete. For example, when existing buildings are replaced, they go into the landfill. With this new type of concrete, old buildings are crushed and recycled to make the new type of concrete. That means the material for today's new buildings are found in buildings we are planning to replace, making our old buildings an unlimited source of construction material! Therefore, the materials needed to construct our new buildings are close at hand and no longer deep in the earth or far away from a construction site! This is important, especially in places like Japan where limestone is not readily available. Concrete is only viable for 100 years, so recycling is a significant improvement.

Just removing the heating of limestone alone saves a tremendous amount of energy since traditionally limestone, the key ingredient in concrete, must be heated to 2,700 degrees Fahrenheit for 3-4 hours.”
RECYCLABLE CONCRETE
Fortunately, this process of crushing and recycling this new type of concrete can occur several times. This would allow a more circular construction process, and the concrete would be sustainable and recyclable as a construction technique.
CARBON DIOXIDE SEQUESTERED
Just removing the heating of limestone alone saves a tremendous amount of energy since traditionally limestone, the key ingredient in concrete, must be heated to 2,700 degrees Fahrenheit for 3-4 hours. The amount of energy involved in heating limestone does not include the energy required to mine for the other raw materials of gravel or sand used in the concrete process. The energy involved in the production of traditional concrete is said to contribute 8% of the world's carbon dioxide pollution. This new process, which crushes existing concrete into a fine powder to react with carbon dioxide in the air, means carbon dioxide is actually trapped in the concrete, removing it from the atmosphere! This is in contrast to the amount of energy and carbon dioxide generated to create concrete the traditional way.

WHERE THIS PRODUCT COULD BE USED
In war zones, e.g., Rafa and Gaza, where almost all the buildings are in ruins, this type of construction technique could be highly beneficial. Building with this new concrete would have the dual purpose of removing countless tonnes of debris while providing the building material for a new city at the same time. Should our Parkmerced ever come to development fruition, this type of concrete could be ideal with the demolition of countless buildings on its 152-acre site. Also, let us not forget parts of Ukraine, where many cities have been leveled.
LIMESTONE IS NOT EVERYWHERE
Concrete is the second most widely used substance used on earth. It comes only after water. Over 4 billion tonnes of concrete are produced every year. So it is important. This new type of building material is called calcium carbonate concrete. It is hoped that new buildings made of this material can be built quickly. Unfortunately, this material is only in the planning stages. However, there are plans for a building with this material in the year 2030, says Professor Maruyama. This construction technique will likely occur first in Japan, where limestone is not readily available.
Please discuss this new concrete with those you know who are in construction or those concerned about the environment. This is another solution for Global Warming—a windfall.
Glenn Rogers, RLA
President, Coalition for San Francisco Neighborhoods (CSFN)
Landscape Architect, License 3223
September 25, 2024