According to a reporter in Tokyo, researchers in Japan have recently announced that they have discovered a method to produce concrete that emits almost no carbon dioxide (CO2) during its manufacturing process.
A team of scientists, primarily from the University of Tokyo and Hokkaido University, stated that this type of concrete material absorbs more CO2 than it emits. They are currently seeking certification from the Building Standard Act for this material, with the goal of practical application in construction by the fiscal year 2029.
Researchers in Japan have found a way to create concrete that emits almost no carbon dioxide during production. (Photo: asahi.com).
According to Takafumi Noguchi, a professor of construction materials research at the University of Tokyo and a member of the research team, the minimum requirements for commercializing CO2-free concrete have been met.
Currently, the production of concrete inevitably involves CO2 emissions.
- Firstly, the production of cement, a key component of concrete, inevitably leads to CO2 emissions. The process of heating a mixture of limestone or calcium carbonate combined with clay and other materials to make concrete also releases CO2 due to the thermal decomposition of calcium carbonate.
- Additionally, burning fossil fuels to reach the required firing temperature of 1,450 degrees Celsius also increases CO2 emissions. As a result, the emissions from the cement industry are significant, accounting for about 4% of Japan’s total emissions.
To mitigate these emissions, scientists have sought to develop a type of concrete that can be produced without high-temperature firing. According to this alternative manufacturing method, concrete waste is crushed and exposed to CO2 to create calcium carbonate from the calcium present in the waste. This mixture is then shaped and compressed to bond and solidify the calcium carbonate particles. In the final stage, heat is used to complete the process.
The scientists have demonstrated that the concrete material produced using this technique emits less CO2 than the amount it can absorb.
In a statement on October 30, team members indicated that their concrete meets the durability criteria set by the Building Standard Act. Researchers are currently assessing the performance of the concrete material when combined with steel pipes and other accessories for use as structural columns.
Professor Noguchi stated that the team will strive to improve production efficiency while ensuring that the quality of the material is not compromised.
