Self-repairing concrete by absorbing carbon dioxide
Massachusetts: American scientists have invented an environmentally friendly concrete that absorbs carbon dioxide from the air and repairs its cracks on its own, thus maintaining its durability for a long time.
The concrete was invented by Professor Neema Rahbar of the Worcester Polytechnic Institute and his colleagues using an enzyme found in human blood, and details are available online in the research journal Applied Materials Today. Published.
During the experiments, the concrete absorbed carbon dioxide from the air and closed its cracks and small holes automatically within 24 hours.
It should be noted that minor cracks in the concrete get bigger over time and can eventually lead to a major catastrophe.
According to Professor Rahbar, in an effort to make better concrete, they learned about a common enzyme “carbonic anhydrides” (CA) found in human blood that quickly removes carbon dioxide that accumulates in cells. Increases blood flow while expelling, so that it can be easily discharged.
The same yeast was added to the concrete powder, which was later finalized by adding water and other ingredients. During the experiments, the “CA” enamel completely closed the one millimeter-sized cracks and holes in the concrete bricks in 24 hours, while maintaining the strength of the bricks.
Previously, special germs (bacteria) have been used to enable concrete to repair itself, but such methods can take up to a month to fill even a small crack, while these methods have also proved to be very expensive. Happened
“CA” When a crack occurs in enzymatic concrete, the enzyme chemically reacts with carbon dioxide in the air to form calcium carbonate (lime) pens that are as strong as concrete.
These pens fill the hole or crack quickly and freeze firmly there, thus not affecting the durability of the concrete.
Professor Rahbar estimates that the technology he has developed will increase the durability of concrete used in construction by 20 to 80 years. While the large amount of carbon dioxide emitted from the concrete industry (by reabsorbing) can be reduced to a reasonable extent.
The technology is currently in its infancy, so it is not possible to say how many years it will take to reach the industrial scale, and how much the concrete will cost.