When is concrete actually dry?

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laying-concreteIt’s difficult to give an exact time for how long concrete takes to dry, or at which stage it is actually considered dry. Concrete is used for different purposes and the use often determines how dry it needs to be. “When is it dry enough to walk on?” has a different answer to “when is it dry enough to drive on?”

There is no accurate answer to when is concrete actually dry which can be extremely frustrating if you are trying to plan a project. So why exactly is it so hard to determine?

The mixture

Concrete is usually made up from aggregate, cement and water. The aggregate mixture varies as does the cement mix. This means that the chemical process that results in the formation of concrete will vary. On top of that the amount of water used is not always accurately measured and this will also impact the drying time.

Some concrete mixtures also have chemical or mineral admixtures to accelerate or slow down the process.

Weather conditions

Weather can really affect concrete drying times.  Hot weather may dry out the concrete too quickly causing the concrete to crack or be too weak. Too much humidity in the air can hinder the drying process and can also have a detrimental effect on the strength of the concrete.

Intended use

The purpose of your concrete will dictate how dry the concrete needs to be. Perhaps you are using concrete to hold a fence post in place in which case you may choose fast-setting concrete and can put your post in place after 4 hours. For a drive the concrete mix may be completely different and you should probably wait around a week before parking a car on it. That said it may be dry enough to walk on within a few hours or it may take much longer to set depending on the drying conditions.

It is generally thought that concrete reaches a “useful strength” within 3 days and the majority of its strength is gained in the first month. However, concrete can continue to harden for many years.

Controlling the process

In order to keep projects on track it is beneficial to control the drying process. The Arxell Drying System allows you to control the temperature and humidity of the drying air. The units form a microclimate over the surface and ensure that moisture removed from the concrete is not reintroduced.

By controlling the conditions around the wet concrete you reduce the risk of drying it too fast or not removing moisture fast enough.

Arxell in construction

The Arxell Drying System offers many benefits to the construction sector. Along with drying concrete it can also be used to dry other building materials such as plaster and screed. Where buildings have been flooded, Arxell can speed up the drying process ready for restoration.

If you would like more information about Arxell, would like to request a demonstration or are interested in purchasing or hiring the system then get in touch