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Concrete with a carbon admixture that can conduct electricity and heat. This could be a simplified description of the principle of five new grounding materials developed and tested by a team of researchers from the FCE BUT Institute of Building Materials and Components Technology. New silicate materials can prevent electrical surges in building structures, improve the earthing of railway networks and warm up roads or pavements.

Conductive silicate materials are similar to concrete or mortar – they are a mixture of cement, aggregate, water and carbon that makes it conductive. However, their properties are not well studied and therefore they are rarely used in construction. “For a year and a half, we have been testing what types, nature and distribution of carbon particles are most suitable for achieving good electrical conductivity and maintaining mechanical properties,” explains Šimon Baránek, a PhD student at FCE BUT.

The new materials can replace the traditional lightning rod and ground the building. However, they are also used for earthing of high voltage electrical networks – i.e. in the infrastructure of railways, trams, transmitters or optical networks. In these places, moisture-driven stray currents often arise, which are nowadays lead underground using steel rods.

“However, maintenance of these reinforcements is costly because these currents carry ions away from the metal materials. The higher the voltage, the faster the corrosion. This corrodes up to 1 cm of iron per year. Therefore, the steel earth wires must be replaced frequently,” adds the PhD student. Electrical stray currents have the same destructive effect on pipelines, including gas pipelines.

However, new silicate materials can spread the current and partially replace the earth wires. Stray currents are lead much deeper and network maintenance costs are thus reduced many times over. Baránek estimates their durability at 20 years. “It is a completely different type of handling current. A 20-centimetre bore is made in the ground, into which our material is poured to create a concrete earth wire,” says the PhD student.

In addition to electricity, silicate materials can also conduct heat and thus serve as heating elements. The FCE research team is now building on previous research in a TACR project and developing silicate building composites with the ability to autonomously control heating. In winter, the technology can be used to heat roads or bus stops.

“Silicate materials can be used to create, for example, bridge plates to which solar panels and a control unit can be attached. Based on the weather forecast, temperature and humidity measurements, the autonomous system adjusts how much electricity flows to the plate. The material starts to heat up and ice formation is prevented,” says Baránek, describing how the new material can increase the longevity of roads that will not need to be treated with chemical sprinkle material.

FCE researchers will now test the ability of silicate materials to shield harmful electromagnetic radiation. “Nowadays, metal sheets are used to eliminate signals in rooms, but their price is rather high. New silicate materials are cheaper and may be include in plasters and coatings in the future. They can be used in operating theatres or homes – for example in bedrooms, where they completely shield the telephone and Wi-Fi network. This will create a more pleasant and healthier living environment,” says Baránek, outlining other uses of this building technology from the FCE.