Self-healing protective coating for cracks in concrete developed

Scientists have reported development of what they describe as the first self-healing protective coating for cracks in concrete; the world’s most widely used building material. Their study on the material, which is inexpensive and environmentally friendly appeared in the ACS Applied Materials & Interfaces journal.

Korea-based Chan-Moon Chung and colleagues explain that protecting concrete roads, bridges and other structures from developing tiny cracks has been a major technological challenge. Cracks allow water, salt used for de-icing and air to enter the concrete. During winter weather, water in the cracks freezes, expands and the cracks get bigger, with road salt speeding concrete’s deterioration. "Although several reports of self-healing anticorrosive coatings for metal protection have appeared, there have been no reports on self-healing protective coating for concrete,” said the scientists.

They described development of such a coating, one that contains microcapsules loaded with a material that seals cracks. Cracking ruptures the microcapsules, releasing the healing agent. Sunlight shining on to the concrete activates and solidifies the sealant. "Our coating is the first example of capsule-type photo-induced self-healing system and offers the advantages of catalyst-free, environment-friendly, inexpensive, practical healing,” the report states.