Self-healing Concrete

About 8% of the world’s carbon emissions come from cement production, and it is surprising yet fascinating how one solution not only minimizes these emissions through the utilization of biotechnology, but is also emerging as a more time-efficient and rewarding approach to modern infrastructure in the long run. Say hello to self-healing concrete!

Now, what exactly is self-healing concrete? The idea is pretty easy to gauge – it’s quite literally in the name – but the process by which the concrete “self-heals” isn’t as straightforward. The history of self-healing concrete dates all the way back to the early 1800s when engineers and architects employed autogenous self-healing in projects. This type of self-healing, which predominantly utilized water, functioned in a way such that unhydrated cement particles within a concrete mix would react with the moisture that's generated from the release of water to trigger the crystallization of calcium carbonate. The calcium carbonate then expands and seals the crack, completing the self-healing process. While simple to execute, the issue with this method is that it only works for microcracks less than 0.3 millimeter wide and possesses longevity concerns, as eventually, every cement particle will be hydrated. 

In 2006, an associate civil engineering professor from Delft University of technology named Henk Jonkers developed a means of repairing concrete with bacteria, pioneering great advancements in the world of construction and architecture. In bacteria-based healing, construction teams or manufacturers store the bacteria developed by scientists in tiny capsules and mix them into the cement mix. The bacteria that’s developed is always dormant as the harsh concrete environment doesn’t allow live bacteria to thrive. Like autogenous self healing, water is still included in the self healing process, but instead of relying on unhydrated cement particles to react with the water, the bacteria releases limestone and fills up the cracks upon being catalyzed by the water. Since bacteria-infused concrete is less prone to irreversible damage, we can minimize the net production of this concrete, simultaneously reducing the net carbon emissions.

Bacteria-based self healing is generally considered a more efficient approach as it accommodates microcracks up to 0.6 millimeter wide and can work even without unhydrated cement particles as the limestone is released from the bacteria. Of course, like all modern innovations, the technique comes with its setbacks, the most prominent one being the financial viability. Concrete containing bacteria that has been carefully grown and then placed in capsules while simultaneously being loaded with foreign nutrients to ensure its survival inside the concrete is usually more expensive than conventional concrete. It is also important to consider the lifespan of the bacteria, as even in good conditions, the bacteria won't live forever. Currently, Europe is the leading producer of bacteria-based self-healing concrete, followed by regions in Asia. While the U.S. is more reliant on manual government check ups for ensuring the sustainability of concrete around the nation, adopting this biotech innovation in architecture is definitely easy to envision for the future of construction in the country. 

If done right, the implementation of bacteria-based construction technology throughout the world could open several windows for both the world of civil engineering and biotech. With this innovation, we can ensure stronger and safer architecture in our cities while also reducing maintenance costs, making up for a good portion of the money endorsed into the development of bacteria-loaded concrete. The transition to this type of concrete not only affects the direction of civil engineering, but also the well-being of the planet with bacteria-based self-healing concrete’s capacity to minimize carbon emissions. Ultimately, self-healing concrete possesses countless space applications and can serve as a means of safer space travel for future missions.

Quiz:

References:

Elgendy, Ibrahim M., et al. “Bacteria-Powered Self-Healing Concrete: Breakthroughs, Challenges, and Future Prospects.” Journal of Industrial Microbiology & Biotechnology, vol. 52, Springer Science+Business Media, Dec. 2024, https://doi.org/10.1093/jimb/kuae051.

‌Purton, Michael. “Cement Is a Big Problem for the Environment. Here’s How to Make It More Sustainable.” World Economic Forum, 2024, www.weforum.org/stories/2024/09/cement-production-sustainable-concrete-co2-emissions/.

“Henk Jonkers.” Mediamatic, 2026, www.mediamatic.net/en/page/187484/henk-jonkers. Accessed 4 July 2026.