The ‘Secret’ to Self-Healing Concrete
For several years, scientists have been developing “self-healing materials” for use in the construction world. These substances repair and restore their own functionality, requiring no external or human intervention. Looking ahead, the global market for these materials is expected to reach $8.23 billion by 2026.
Hydrogels and epoxy resins are just some of the self-healing materials that have found construction applications through roofing materials and concrete. Researchers discovered a bacteria group which, when embedded in concrete, aids the material to self-heal cracks when they appear. This concrete is currently being used in the construction of various bridges, tunnels, residential buildings, and other new structures. The self-healing marine concrete service life ranges between 60–94 years compared to only seven years for traditional concrete, exponentially extending the life of concrete-based structures, like hydropower dams for instance.
Check out this video from PNNL featuring self-healing concrete:
For even more information, check out The Secret to Super Strong Concrete Is... Bacteria? video from the SciShow.
Polymers, chain-like molecules found in animals, plants and plastics, are added in the process of making concrete. These bacteria form soft, flexible bonds with cement components, creating new properties. “Sporosarcina pasteurii” bacteria found in the bottom of lakes formed by volcanoes, are very alkaline which is good for concrete. They also excrete “calcite” which is a mineral that makes up concrete. The new properties cause just enough flexibility to bring about “self-healing”. When cracks form, the polymers move or migrate to the crack and form a tight bond. These newest self-healing bacteria can heal over and over, underground and under high temperature, and last for 200 years. Cement with such self-healing properties can be produced at near the cost of current cement production and can save up to $3.4 billion a year in repairs!
Additional reading about self-healing concrete:
- Asian Scientist Magazine: Concrete Doped With Microbes Gains Durability
- Market Watch:Self Healing Materials Market Size, Share to Reach 8.23 billion USD by 2026
The most used resource on earth is water. Second to that is concrete. Cement production causes about 9% of the world’s CO2 emissions. Considering the increased need for construction development worldwide, self-healing concrete would help reduce CO2 emissions by reducing the need to replace and repair concrete. Self-healing concrete will be on the market in three forms: concrete; repair mortar; and liquid spray which can be directly applied to cracks in existing structures. What if there were self-healing properties that could be applied to wire used in the electrical construction industry? Maybe those self-healing bacteria could speed their own processes to repair damaged or broken wiring in less time than it takes to schedule and dispatch a repair truck…
NECA Technology – the Project for Applied and Disruptive Technology, explores the world of technology and keeps members informed of what’s happening today, and of what will be launched in the not-too-distant future. Dr. Joey Shorter has an extensive background in education and experience in translating the work of academics into understandable, practical ideas.