Concrete conducts electricity

Concrete is a mixture of cement, gravel, and water, which when mixed and then hardened forms a strong material. The electrical conductivity of concrete is the property that allows it to conduct electricity. Concrete is not something that’s normally thought of to be an electrical conductor but in actuality it is. Concrete conducts electricity due to the ions in it.

Several factors, including resistivity and water content, can influence how well concrete conducts electricity and the methods for increasing or decreasing its conductivity.

What property of concrete makes it conductive?

Whereas concrete can become an electrical conductor, natural concrete is much more of a resistor ( Electricity will rarely pass through resistors due to a large amount of power it takes to do so).  Dry concrete made from only the usual concrete ingredients (sand, water, natural aggregates, etc.) is a terrible conductor of electricity and can even be used as an insulator. While many materials become more conductive as they heat up, concrete does the opposite, increasing its resistance to absurd levels.

The first thing that happens during the concrete mixing process is a sharp drop in resistivity as water is added to the dry mix. The resistivity of the concrete then drops, sometimes a hundredfold, as it is mixed and dried. Because each batch of concrete loses conductivity at a different rate and reaches different resistivity heights, this process is highly unpredictable. Concrete’s conductivity can be increased by increasing its water content. However, the more water in the concrete mix, the weaker it becomes. This can be a serious issue depending on the intended use of the concrete. If the concrete only needs to be slightly conductive, however, this is usually a great solution to the conductivity problem.

Factors that affect conductivity

Factors that affects conductivity

The size and shape of an object can also have a significant impact on conductivity. A thick object conducts better than a thin one, and a short object conducts far better than a long one.

Finally, an object’s temperature can significantly increase its conductivity. When heated, some resistors, such as glass, become extremely good conductors. Superconductors, on the other hand, conduct electricity extremely well at low temperatures.

Concrete, with the exception of scientifically altered concrete, does not have much conductivity on its own. However, there are a couple of construction situations that can make insulating mill concrete much more electrically conductive. When concrete is placed in a humid environment, it can easily become conductive.

Concrete is good at absorbing water, and as previously stated, concrete is more conductive when it contains more water. This means that if it is placed on wet ground or in a rainy environment, it can become a conductor of electricity as long as it remains wet.

Another circumstance in which concrete becomes conductive is when it is fused around steel bars. Almost all non-trivial concrete structures contain some form of reinforcing bar, and the presence of metals in concrete can make it a very good conductor. This is most likely due to the steel’s ability to conduct electricity, allowing electricity to use the steel as a kind of highway through the concrete. Because of these two extremely common scenarios, most concrete used in many construction projects are at least somewhat conductive, even if it is not naturally so.

The Pros & Cons Of Electrically Conductive Concrete

Conductive concrete is a ground connection for lightning rods. Lightning rods must have a conductive counterpart in the ground to redirect the lightning they catch, and in many places, the ground is not always very conductive. In those cases, a building’s concrete foundation can often serve as the base for its lightning rod, protecting the people living inside.

Another valuable use of  Conductive concrete has a wide range of applications. For example, electrically conductive concrete can be used to heat roads and make them safer to drive on in the snow. This technology can even be repurposed to provide radiant heating for homes in cold climates.

It’s important to remember that even if the concrete you come into contact with every day doesn’t appear to conduct electricity, it may. Even if you know it’s natural cement, never rely on it to keep you safe from live electricity. Unless it is lightning and you are safe inside your home. In that case, the concrete may be on its way to saving your life. You can contact our team of experts if you have questions or concerns about the conductivity of concrete