The electrical curing of concrete is done by employing the heat generated from an alternating current to raise the temperature of maturing concrete.
The concrete is heated up using an AC till up to about 90ºC because ten degrees more will cause the water to turn into steam, which can cause damage to concrete. With this heat, the hydration reactions of maturing concrete are thermally accelerated.
Now, the curing can be done in three ways. The first is the most popular one :
- Electrode plates or a network of electrode plates are joined to the faces of the concrete member, and an AC of generally 30V or 60V is passed for a period of at most three days. Larger curing times have been seen to be uneconomical even in the most favorable conditions.
- A larger magnitude and lower voltage AC as compared to method one is passed only through the steel reinforcement in the concrete. This provides for a slow but steady and uniform distribution of heat.
- Large electric pads surround the concrete much like shuttering. Current is passed only through the pads, and they are heated up. The heat, in turn, heats up the concrete very uniformly.
Although it’s quite an impressive technique of concrete curing, it is rarely used because it’s generally uneconomical. It is only used in cold climates where concrete is very susceptible to freezing and thawing within the first week. Also, natural curing is not very easy in cold weather. The technique was even born in Sweden.
Another use is where cost is not, but time is the most important consideration. Maybe in large projects and in real estate.