Self Healing Concrete by Using Bacteria

Introduction from Undergraduate Research Day Poster: Concrete is the second most used substance in the world, second only to water (Gagg 2014). Concrete is crucial to modern building and architecture and has been used since the times of the ancient Romans. Unfortunately, concrete does not last forever and can crack and break down. Since it is so ubiquitous, the problem of how to fix or repair concrete is well studied. Traditionally, repairing concrete is possible but has some drawbacks. Self healing concrete can help prevent the degradation that is the cause of most concrete damage. Self healing concrete comes in a variety of forms from chemical to biological (Amran et al 2022). One promising method is to make concrete that can self heal by adding certain strains of bacteria. Certain species of bacteria produce carbonate which, when combined with calcium ions, make calcium carbonate, a main component of concrete. Several factors can affect how much CaCO3 bacteria can produce. In order to produce CaCO3, bacteria need 3 ingredients. Urea is required for the urease enzyme, present in some bacteria, to convert into CO3 2- . A source of calcium is needed to combine with the CO3 2- to form CaCO3. Finally, a source of nutrients is required to keep the bacteria alive and provide energy.