The Password is: 'Self-Healing Concrete'
"Self-Healing Concrete Uses Sunlight to Fix Its Own Cracks," Technology Review reports:
Even the tiniest cracks on the surfaces of concrete structures can lead to big problems if they aren’t immediately repaired. Now researchers have demonstrated a sunlight-induced, self-healing protective coating designed to fix cracks on the surface of concrete structures before they grow into larger ones that compromise structural integrity.
More resilient concrete structures like bridges and overpasses could save governments billions of dollars in annual expenses on repairs and maintenance. In recent years, a growing field of research has focused on developing self-healing mechanisms for a range of materials, concrete included. Several approaches to self-healing concrete have emerged, including attempts to engineer self-healing mechanisms into concrete itself. But the authors of a new paper published in ACS Applied Materials and Interfaces say their demonstrated technology represents the first example of a self-healing protective coating for concrete.
Previous approaches to self-healing concrete systems have mostly focused on restoring strength to damaged concrete, says Chan-Moon Chung, a professor of polymer chemistry at Yonsei University in South Korea who led the research. His group chose to focus on protecting the surface, where tiny cracks can allow water, chloride ion from deicing salt or seawater, and carbon dioxide to penetrate the structure, which can lead to harmful deterioration.
The new coating contains polymer microcapsules, filled with a solution that, when exposed to light, turns into a water-resistant solid. The idea is that damage to a coated concrete surface would cause the capsules to break open and release the solution, which then would fill the crack and solidify in sunlight.
Based on a recent video at Reason TV, I certainly hope they test this new technology in L.A. first:
Found via the blogger who likes to quip, "Well, it is the 21st century, you know."
Now, how do we create an outdoor paint that can shrug off graffiti?