Embedded bacteria may soon keep cracks out of our concrete
Concrete is a pretty useful and practical building material. It’s strong, not too hard to make and relatively cheap. The problem is that when it does start to break, it can’t really be repaired and usually has to be replaced instead, which can become difficult and costly. Fortunately, some embedded bacteria might be able to help us with all that.
The bacillus and/or sporosarcina bacteria would be contained in tiny capsules and mixed into the concrete when it was being poured. Inside each capsule would be food for the bacteria, but they would be dormant at the time, leaving that little snack alone for a rainy day. When a crack forms, rain or other moisture will be able to seep down to the capsules, activating the bacteria, which should then start eating their packaged provisions. As they eat, they’ll start pooping out hard limestone, which will then act as a putty to fill part of the crack and prevent further water seepage.
The bacteria should be able to be on standby for up to 200 years, well beyond the expected lifespan of most concrete slabs. Even slowing damage would be an improvement, saving tons of money and effort in the process.
My kindergartner asked: Will the bacteria on the surface of the concrete be activated in the first rain? Will they fuse sidewalk slabs together as they fill the intentional gaps there? Unfortunately, it’s not clear how they’d make sure the bacteria capsules are kept from immediate exposure to moisture, unless that’s just accounted for in the project’s design.
Source: This futuristic concrete heals itself with build-in bacteria by Mary Beth Griggs, Popular Science