Everything you need to know about the Bio-Concrete
For each construction project, from the structure of bridges and subterranean parking garages to the foundation of skyscrapers, concrete is still one of the primary materials employed.
Due to its ease of use and long-term durability, concrete building is a regularly used option worldwide. But in addition to its numerous advantages, particularly in the building industry, it also has a lot of disadvantages. That is why self-healing concrete is of much importance.
Importance of Self-healing concrete
Although concrete is the most crucial building material for the construction industry, many concrete structures have had various forms of cracking issues throughout the course of their lifetimes.
Because water enters into ordinary concrete and begins to degrade it and corrode the steel reinforcement, little cracks appearing on the surface of the concrete give the impression that the entire building is susceptible.
This substantially reduces the lifespan or durability of any construction. Concrete can sustain compressive forces quite well, but not tensile forces, which is a well-known fact. Steel reinforcement is used to support concrete structures and resist tensile stresses because when concrete is subjected to tensile tension, it begins to crack.
Marine structures and subterranean basements are two examples of buildings constructed in high-water environments that are particularly susceptible to corrosion of the steel reinforcing. Because salts used to de-ice the roads seep into the gaps in the structures and can speed up the corrosion of steel reinforcing, bridges are also susceptible to corrosion issues.
Tensile pressures may cause cracks in the majority of civil engineering structures, and they can appear quite soon after the building is built.
By using a concrete mortar that is adhered to the damaged surface, traditional concrete structures may be repaired. Metal pins may occasionally need to be used to secure the mortar to the old structure's fissures in order to prevent it from separating.
As repair work is sometimes quite challenging, it takes a long time and costs a lot of money. If the repairs are underground or higher up, it can require more effort to get into the building.
How the self-healing work?
Concrete that is capable of self-healing fixes itself by organically creating limestone to fill in surface fissures.
The bacteria's spores fertilize when they come into touch with water and nutrients, which happens whenever the concrete is broken and water begins to seep into the gaps that emerge in the concrete. The calcium lactate is first fed to the bacteria.
The soluble calcium lactate is changed into insoluble limestone when the bacteria consume oxygen. On the fractured surface, the limestone hardens, closing it.
It mimics the way that osteoblast cells in the human body spontaneously repair bone fractures by mineralizing to re-form the bone. Another benefit is the oxygen use during the bacterial conversion of calcium lactate to limestone.
As is well knowledge, oxygen plays a significant role in the corrosion of steel. However, in this instance, bacterial activity has completely eaten all of the oxygen, boosting the durability of steel-reinforced concrete projects.
Aspects of Bioconcrete in construction
The idea of bacteria healing concrete was first introduced by US academicians. As the commercial engineering industry was not interested in such a product, testing and implementation of the idea were not pursued further.
But after recent research and development in bio concrete, a number of major businesses have partnered with Delft University to build self-fixing concrete applications. The building business is now providing investment funds.
Therefore, researchers at Delft University are now creating self-healing concrete goods for certain civil engineering markets that will not compete with one another. They are developing a product for industries such as maritime constructions, concrete floors, structural basement walls, and highway bridges.
Benefits of Bio-concrete
1. By using bio concrete, the overall maintenance costs of a structure reduce, and as a result of using bio concrete, the concrete becomes stronger and more durable over time.
2. The permeability of this concrete is lower than that of conventional concrete.
3. Compared to conventional concrete, it has a lower water absorption rate.
4. It provides excellent protection from freeze and thaws assaults.
5. The likelihood of corrosion or reinforcement is almost nonexistent.
6. Cracks can be repaired effectively.
7. In essence, it substantially improves the structure's durability.
To learn more, watch the following video tutorial.
Video Source: TU Delft
Drawbacks of Bio-concrete
1. Bio-concrete or self-healing concrete is more costly than regular concrete.
2. Not every setting is ideal for bacterial germination.
3. Costly research is required to see calcite precipitation.
4. Because the bacteria employed in concrete are bad for human health, their use must be restricted to specific structures.
5. The codes of design do not currently provide any design recommendations for bacterial concrete.
Because of its environmental friendliness, self-healing capabilities, and increased structural durability, self-healing concrete technology has proven to be superior to many traditional technologies. We now have a better grasp of the potential and restrictions of biotechnological uses on building materials thanks to the efforts of several researchers.
Various cementations and stone materials have shown improvements in compressive strength, permeability, water absorption, and reinforcement corrosion. This technique makes cementation formation exceedingly simple and practical. However, further study is needed to increase the technology's viability from an inexpensive and scalable practical standpoint.