This concrete... is alive!

It's not a myth.

There's a way to do that: just hire... specialized bacteria. They will do all the work, and a landing ground will emergence like a dream. No, it's not a joke. Americans have already successfully tested specified solutions in the framework of a concept supported by the defence Advanced investigation Projects Agency. The task was named “Medusa” due to an analogy to an ancient mythic being who turned everything that lives into stone. The thought of Americans is the same: to turn uncertain ground into a hard shell that will be strong and unchangeable adequate to let safe landing. The procedure is not complicated at all: you gotta distribute adequate bacteria around the site and then feed them with salt water, deliver urea and calcium – and these are more easy accessible and cheaper than cement. The effect is to say, brick: bacteria begin a chemical process, the final consequence of which is simply a hardened landing site.

Tests technology They had already conducted specialists from Biomason in July 2021 in collaboration with the American military on the Andersen Air Force base on the Pacific island of Guam. The tests proved the usefulness of this method: it manages to prepare a landing ground that can withstand the launch of even dense transport machines within 96 hours.

Self-regeneration

But Building temporary infrastructure is 1 thing – what else is keeping it in good condition the already existing one. Apart from the undeniable advantages of concrete, it besides has its drawbacks: over time it crumbles, cracks and begins to lose its main feature – endurance. For this reason, concrete infrastructure – runways, landing areas, manoeuvring areas, exercise areas, marinas and ports – needs to be regularly monitored and renovated if necessary. Since concrete is simply a basic building material besides in the military, it is becoming serious: the cost of maintaining, refurbishing and refurbishing military infrastructure goes into large millions all year.

I think it's best if she's on her own. It is for this reason that very extended investigation is being carried out on materials that will let this, i.e. those able to rebuild their own structure after damage. “In Poland we do not yet have a good name for what is referred to as self-healing materials in English,” explains Prof. Jerzy J. Sobczak from the Faculty of Foundry of the AGH University of discipline and Technology in Kraków. “I have met quite a few terms: self-healing, self-regenerating, self-healing, self-renewable, self-ordering,” he adds. due to the fact that a immense part of military infrastructure is created utilizing concrete, investigation on the alleged self-regeneration of this material seems peculiarly important. "The concept is moving towards utilizing the alleged healing agent. erstwhile damage, rift or crack occurs in the material, it should have the ability to automatically reconstruct functionality – the prof. points out.

Various methods of self-regeneration of concrete are tested. For example, a peculiar concrete mix is prepared, which contains microcapsules with a healing agent. “When the crack occurs, the microcapsules begin to work,” explains Prof. Sobczak – the healing agent leaks into these cracks, fills them, and thanks to the catalyst that is in the concrete, the chemical process that causes the rift to cross. Another method is to introduce peculiar mineral additives into the concrete mix. – In the event of the formation of a rift, mineral agents expand, swell, besides in the presence of water, and yet fill in the crack – says Prof. Sobczak. Methods are besides tested utilizing composites, especially alleged multi-functional materials. – More roughly, they usage the mechanics of action of the ECC [Engineered Cementitious Composite], which converts cracks into microstains, and these are no longer so dangerous for the full material," says the professor.

Biomason employee, as part of Medusa's project, “feeds” bacteria to harden the surface of the runway. Durham, North Carolina

Bacteria in action

The most advanced and promising work seems to concern the alleged biobeton. It uses specially selected strains of bacteria, capable of precipitation calcium carbonate, a chemical compound which is part of building materials, including, above all, cement. The methods of his preparation are different. – 1 involves mixing concrete with bacteria closed in peculiar capsules containing urea and calcium salt – says Dr. Agata Goryluk-Salmonowicz from the Department of Biochemistry and Microbiology of the Warsaw School of Economics. These bacteria form alleged spores, or peculiar forms to last under adverse environmental conditions specified as advanced salinity or deficiency of water. – In this form, the bacteria can last months or even years, waiting for conditions beneficial for improvement – explains Dr. Goryluk-Salmonowicz – And erstwhile water and nutrients appear, the spore germinates and forms a bacterial form capable of multiplying.

Once the concrete is poured out and frozen, the spores are able to sleep, but erstwhile there is water in their vicinity (the crack of the structure), they produce an active bacteria. – Bacteria begin to process metabolic processes utilizing the nutrients contained in the capsule. The byproduct of these reactions is calcium carbonate, which forms hard structures. The precipitated calcium carbonate crystallises and fills the harm – describes Dr. Goryluk-Salmonowicz. Another way of utilizing bacteria is to place the alleged binding solution in place of rupture. It contains bacteria and nutrients, i.e. what is needed to trigger a process, the consequence of which is the ‘treatment’ of concrete cracks.

In addition to the above mentioned programme ‘Medusa’ The Americans besides lead others. Bio-inspired Restoration of Aged Concrete Editorials, for example, seem very promising. The way to increase the service life of concrete military infrastructure is to form any kind of vascular strategy in concrete itself, following the pattern existing in multicellular organisms. It is assumed that this will give concrete the ability to self-regeneration not only on the surface, but besides deep down, before the crack becomes visible.

In collaboration with the U.S. Department of Defense, the programme "Engineered surviving Marine Cement" is besides being developed, which tests the usage of bacteria to regenerate military infrastructure in the marine environment (such as marina or breakwater), and even stabilize the seabed in delicate locations. DARPA besides sponsors the Reefense programme, which aims to make self-regenerating structures mimicking sea reefs. Their task will be to supplement or even replace conventional concrete in the construction of coastal fortifications and defend marine military infrastructure from erosion and demolition caused by storms.

Not so far ahead

What about prospects? - That's it. technology requiring further research. The basic parameters of the process, especially the composition of the average in the capsule, should be worked out so as not to lead, for example, to corrosion of the reinforcement, which can be the scaffolding of the concrete structure – admits Dr Agata Goryluk-Salmonowicz. The problem is besides the cost of production of biobeton, much higher than conventional material. – It is worth remembering, however, that the constructions from the biobeton will not require repair or costly renovations, as it is self-regenerating concrete – the expert concludes.

Since many technological centres in the planet are working on this technology, its refinement and then extended application – besides in the military – seems not so distant. Its advantages are abundant.