Classic concrete is a non-conductor. However, when a suitable carbonaceous material is added to concrete, it can become a surprisingly successful conductor. Nanosciences are very suitable for this purpose, which create electrically conductive concrete and at the same time are cheap. Concrete with nanoclayings heats up significantly when passing through an electric current, which can be used in many different applications, both outdoors and indoors.
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Conductive concrete with nanosets. Credit: Andrew Logan / MIT.
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Today, concrete is a very versatile and most common construction material. It is used all over the world and almost everything is built from it. However, this certainly does not mean that the concrete is perfect and that it cannot be improved. Experts from the American MIT Institute have added nanocarbons to the cement to create concrete that is electrically conductive.
Traditional concrete is a typical non-conductor. However, materials scientists have recently been trying to change this and create conductive concrete. It usually solves this by adding some form of carbon. For example, concrete has already appeared, which automatically melts the fallen snow. Nancy Soliman and her colleagues have now chosen nanocarbonate (nanocarbon black) as an admixture in concrete, a cheap carbon material that dramatically increases the conductivity of concrete. It is enough if the nanoset makes up about 4 percent of the volume of the concrete and it already conducts an electric current. Such concrete is also heated by the passage of an electric current.
Logo. Credit: MIT.
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According to the authors of the study, Joule heat is generated in their concrete, which is generated by an electric current, specifically by interactions between passing electrons and atoms in a conductor. The electrons of an electric current, accelerated by an electric field, transfer part of their kinetic energy to the atoms of the conductor and thus cause their vibrations. And these vibrations are nothing but heat, so the conductor heats up as an electric current passes through it.
Concrete samples with different amounts of nano-deposits. Credit: Andrew Logan / MIT.
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Experiments have confirmed that nanoset concrete is very efficient in generating heat. If a current of even low voltage of 5 V is applied to it, it heats up. In this case, the nanoset concrete samples were heated to about 41 ° C. According to the creators, such an effective material could be used not only in the outdoor environment when melting snow and ice, but also in indoor technologies.
According to researchers, this concrete could, for example, become an ideal material for heating floors. Nowadays, such heating is usually solved by a system of pipes with heated water. However, such systems are difficult to build and maintain. If the concrete of the floors itself became the heated material, this would significantly simplify the construction of the floor heating and would also improve the operation of these systems. Concrete with nanocups also promises homogeneous heat generation, thanks to the very good dispersion of nanocups in such a material.
Literature
Physical Review Materials 4: 125401.
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