
How Long Does Concrete Take to Dry?
Posted By:Dynamic Concrete Pumping , Date: Apr 22, 2019
Concrete is one of the most widely used building materials, known for its durability and strength. It generally takes 24 to 48 hours to set, though it can take longer depending on the environment. However, concrete drying is a continuous process, and it continues to harden over time.
Here are some facts about how long it takes for concrete to dry and what you should expect regarding concrete setting time.
What Is Curing?
Although you might be able to see the visual effects of curing on the concrete’s surface, changes also happen at various depths, down through the concrete’s core. The end result is the hard, resistant surface we rely on for driveways, sidewalks, foundations and other surfaces. Curing and drying are not the same thing. While curing gives concrete its physical properties, drying takes place during and after the curing process to help the concrete reach the specific conditions required for its intended application.
There are multiple curing methods for concrete, but water curing and membrane curing are some of the most prevalent:
- Water curing: Uses water pouring, sprinklers, ponding or immersion to maintain continuous moisture levels in the concrete.
- Membrane curing: Liquid membrane is applied to the concrete, where it solidifies into an oil-based or water-based layer to eliminate evaporation.
Other curing methods include left-in-place forms and covering concrete with special blankets or sheets.
What Makes Concrete Harden?
Changes happen inside the concrete mixture both during and after the curing process. When cement is mixed with water, rock-like crystals begin growing, giving the soon-to-be concrete its strength. The temperature range and moisture levels must be within the correct limits — the wrong amount of water causes cracks or shrinking and prevents crystal growth. When the concrete gets too cold, the crystal reaction process stops entirely.
Specific hardness levels vary depending on the concrete mixture’s specific ingredients and proportions. Some concrete pourers rely on strength and hardening accelerant methods like steam, heating coils or heated forms. Never attempt this on your own, as it’s not suitable for every application, and incorrect acceleration can leave you with damaged concrete and wasted materials.
Concrete starts hardening as soon as it’s poured, but it’s far from ready. Give it at least 24 hours of concrete cure time before allowing any light foot traffic and even longer before putting any significant weight on the surface.
How Long Does Concrete Take to Cure Completely?
The most significant hardening occurs within the first 28 days. After the initial curing period, the rate of hardening slows down considerably but can continue for years if enough moisture is present.
The concrete hardening process comprises a reaction from cement particles mixing with water. The concrete becomes harder as the cement bonds with the water molecules. Very small moisture bubbles are trapped within it, making your concrete harder over time.
How long it takes concrete to dry or set will depend on its specific purposes. For instance, the amount of time it will take to park or drive on concrete without your vehicle sinking will differ from the time needed before you can walk on it without leaving footprints.
Nevertheless, concrete takes a short time to be ready for use. It can take between 24 and 48 hours before you can walk on it without leaving footprints. After a week, your concrete will have cured to at least 70% of its full strength. At this point, it will be solid enough to drive on without resulting in damage. However, it is best to hold off driving heavy vehicles or placing equipment on the concrete surface until it has fully cured — typically around 28 days.
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What Factors Impact the Amount of Time Concrete Takes to Set?
How long does concrete take to dry under different conditions? Concrete setting times are not necessarily consistent across situations. How long you should let concrete cure depends on several factors that can affect drying time.
Moisture
Water is essential to the chemical reactions that form the hard crystals that solidify into concrete. Insufficient water results in structurally weak concrete, while too much water is disruptive and can cause cracks, divots, shrinking and flaking.
Avoid pouring concrete if rain or storms are likely — puddling and water channels can wear down uncured concrete, creating imbalanced moisture levels and causing irreversible damage. If your concrete has had at least six to eight hours to cure before a quick rainshower, it should be OK — but younger mixtures or heavier, prolonged rains could cause trouble as it absorbs the excess water.
Don’t apply anything to your concrete while it’s still curing — paints and stains can also interfere with moisture content and chemical processes.
Temperature
Hot and ambient temperatures are usually ideal for concrete curing, as it helps moisture evaporate faster. That said, excessively high temperatures aren’t safe to work in, especially if you’re pouring large areas of concrete at a time. Too much humidity may also disrupt moisture and make temperature control difficult.
Cold temperatures are less forgiving for concrete curing — when temperatures are below 4 degrees Celsius or 40 degrees Fahrenheit, special concrete pouring techniques are required. Below -6 degrees Celsius or 20 degrees Fahrenheit, it’s best not to pour concrete.
While planning your concrete projects around the warmer seasons and temperatures is ideal, cold spells aren’t always predictable. If you’re working in the spring or fall where dips in temperature are common, consider investing in insulation for uncured concrete and keep it safely sealed from cold temperatures for at least a few days, if not longer.
Mix Design
Some concrete mixtures cure faster than others. These “quick-drying” formulas require specific techniques to mix and pour correctly, and they don’t guarantee the same concrete strength and stability as traditional concrete formulas.
The same is also true of adding accelerants to concrete mixtures before curing — it may work for some small applications, but don’t expect your final result to have the same durability.
Leave Your Commercial Concrete Projects to Us
The curing time for concrete depends on several different factors, and even small missteps could force you to redo your project. Save yourself the hassle and materials, and give the team at Dynamic Concrete Pumping a call. We’ve got over four decades of industry experience and are equipped to take on commercial projects of all sizes and applications.
Request your free quote today!
-Updated 12/23/24