What is Self Healing Concrete?

Hey there,

Did you know there was something known as self healing concrete? I certainly did not know what is self healing concrete until a few months back when my uncle told me about it during the renovation of his ancestral home. He told me that self-healing Concrete is characterised as having self-healing characteristics. Concrete's ability to self-heal or self-repair enables crack rectification and repair using either autonomous or autogenous techniques. All of these actions are defined by concrete's durability, which is one of its properties. The materialistic quality of durability aids concrete in defending itself against any chemical or physical attacks. There are more chances for cracks to form when durability declines.

Self healing concrete used in construction

To create self-healing concrete, scientists and engineers from all over the world have experimented with a variety of healing chemicals. Bacteria, sodium silicate, and even fungi have all been used as healing agents in the past.

1. Bacteria-Based Self Healing Concrete Structures: Henk Jonkers, a microbiologist and professor at the Delft University of Technology in the Netherlands, created self-healing concrete. He spent three years experimenting before discovering the ideal cure: bacillus. In concrete's very alkaline environment, the bacteria will flourish and create spores that may survive for up to four years sans food or oxygen. In order to feed the bacillus so they can generate limestone to heal fractures in the concrete, Jonkers completed his innovation by introducing calcium lactate to the limestone concrete mixture.

2. Sodium Silicate-Based Self Healing Concrete Structures: Together with University of Rhode Island lecturer of chemical engineering Arijit Bose, engineering student Michelle Pelletier developed a similar self-healing concrete. These capsules break open and emit sodium silicate as cracks develop in the concrete. The crack is repaired and hardens in about a week thanks to a calcium-silica-hydrate gel that is created when the chemical reacts with the calcium hydroxide in the concrete.

3. Fungus-Based Self Healing Concrete Structures: Ning Zhang of Rutgers University and Congrui Jin, Guangwen Zhou, and David Davies of New York's Binghamton University developed a fungus-based self-healing concrete after drawing inspiration from our own physiological processes. Trichoderma reesei fungal spores are used to make their concrete. When the first cracks show up, the spores lie latent until then, at which point they start to fill in the spaces.

I hope now you understand what is self healing concrete.