Used by the Roman Empire to build architectural wonders that have stood the test of time, concrete has proven to be one of the most durable building materials developed by man. However, over time, its degradation can cause large cracks that require repair. But is it realistic to think that one day it will be possible to rely on self-healing concrete capable of restoring itself?
Well, that day may not be as far away as it might be thought. For several years now, a Dutch research team from Delft University of Technology has been working on a “living” concrete that contains bacteria with the ability to seal cracks as they form. Soon, it may no longer be necessary to have cracks repaired inside your home?
Dormant bacteria integrated into the concrete recipe
To make this self-healing concrete, dormant Bacillus and/or Sporosarcina bacteria, as well as their food source, calcium lactate, must first be packaged in the form of tiny granules that take the appearance of a fine white powder. This powder is mixed with wet concrete, which can then be poured into the formwork.
When a crack forms and water begins to seep in, the bacteria comes out of its dormant state, becomes active, and begins to eat the food. The bacteria then excrete a load of hard limescale that fills the crack and prevents the water from doing more damage.
Although many forms of concrete begin to decompose after 20 to 30 years, these bacteria can remain dormant for 200 years in the absence of food, which can extend the life of a concrete structure for decades after it has exceeded its useful life.
Incidentally, this revolutionary concrete has the potential to significantly reduce costs in terms of health monitoring, damage detection , and maintenance of concrete structures. For now, the main element that could hurt the popularity of this material is the cost of biological agents, which increase the price of concrete by about 50%.
Laboratory tests that proved conclusive
At present, due to the cracks that can form in the concrete, it must be reinforced with steel reinforcement. However, if water seeps into the concrete and reaches the steel rods, corrosion can form and threaten the strength of the material.
In fact, the construction industry currently tolerates the presence of cracks of less than 0.2 mm since they do not cause any real loss of strength. It is therefore the larger cracks that the researchers want to seal by adding bacteria to the concrete. In the laboratory, they were able to repair cracks with a width of 0.5 mm, two to three times larger than those tolerated by current standards.
Waiting for self-repairing concrete to hit the market
Of course, there is still a lot of research to be done before this bacteria-containing concrete can be used on a large scale. However, the day when cracked concrete will repair itself may not be far away!
In the meantime, you can always entrust the repair of your cracked concrete foundations and slabs to Groupe Fissure Expert. The 10-year warranty offered on crack repairs is a guarantee of the quality of the execution of the corrective work. Do not hesitate to call on our services.
Need a Crack Repair Expert?
If you notice cracks on your foundation, it is important to act quickly. Fissure Expert offers professional foundation crack injection services throughout Quebec. Call a certified foundation crack contractor for a free estimate. We serve Longueuil, Sherbrooke, Laval and many other cities.