How Long Does It Take Ready Mixed Concrete To Dry?
October 08th, 2023
Here at SRC Readymix, part of the SRC Group, we pride ourselves on our high-quality ready mixed concrete but starting with a good concrete mix on your project is only half of the story. For concrete to achieve its renowned strength and durability, the material must be dried and cured correctly. In this post we explain how long it takes ready mixed concrete to dry, what the difference between drying and curing is, and what you can do to speed up concrete drying times.
The Basics Of Ready Mixed Concrete
Ready mixed concrete is exactly what it sounds like – concrete you purchase that is already mixed. The alternative to ready mixed concrete is mixing concrete yourself using raw materials. Ready mixed concrete is used in all types of building projects because of the advantages it has over self mixed concrete. You can read about these benefits in our previous post here, but in summary, ready mixed concrete:
- Saves valuable time
- Provides value for money
- Provides quality and consistency
Concrete, both ready mixed and products that require self mixing, have the exact same ingredients – aggregates such as sand or gravel, cement, and water. The cement and water are mixed to form a paste and then aggregates are added – the result is a mixture that sets into a solid, rock-like material known for its strength and durability.
Mixing concrete requires the exact amount of the right ingredients, or you will end up with a poor result. When concrete fails, it’s usually due to improper mixing and a lack of quality control.
Another reason for concrete issues or failure is improper drying and curing. When working with concrete, you need to know the correct drying procedures, issues you may run into with drying, and how you can accelerate the drying process.
Understanding the Drying Process Of Ready Mixed Concrete (Hydration)
Once ready mixed concrete is poured, water evaporates and the concrete starts to harden. A basic explanation but the important part to note is that this process shouldn’t happen too quickly. The aim is to let water slowly evaporate, this will prevent cracks and failures in your newly poured concrete.
When concrete is poured it goes through an initial setting stage, drying and curing. It’s important this process is followed carefully to prevent cracking and premature surface erosion.
The curing of ready mixed concrete is the most important step and isn’t as simple as leaving the concrete to dry on its own. As mentioned earlier, concrete needs to harden gradually by slowing down water loss.
Typical Drying Times For Ready Mixed Concrete
Here are the different phases concrete goes through when drying:
- Initial setting – concrete will set enough to walk on within 24-48 hours. You can walk on the concrete and not leave any footprints, but the process isn’t over yet!
- Drying – after 7 days, most concretes will have cured to around 80% of their design strength. This is not the case for concrete that uses blended cement.
- Curing – curing is the longer process concrete goes through to reach its maximum potential. After 28 days, most concretes are considered cured enough to be considered ‘finished’ and will have exceeded their design strength.
Factors Influencing Ready Mixed Concrete Drying Time
The concrete drying times given above are guidelines because there are factors that can influence concrete drying times, and it’s important to consider these factors when working with the material.
Factors that can influence concrete drying times include:
- Water/cement ratios
- Ambient conditions and temperature
- Humidity levels
- Concrete thickness
- Curing methods used
- Cement type used
Because the drying process relies on the steady evaporation of water from concrete, environmental conditions can have a significant impact on drying. Hot and dry conditions will make water evaporate too fast, as will high winds. High humidity levels will stop water from evaporating effectively.
Curing Concrete For Durability And Maximum Strength
In a study on the effectiveness of concrete curing methods, researchers found concrete that wasn’t cured and was left to air dry, attained only 66% compressive strength after 28 days. So almost half of the concrete’s strength was lost!
This is why there is so much emphasis on the curing procedure for concrete, and why you need to be aware of environmental conditions that can affect drying.
We won’t go into curing methods in detail here – because it deserves an article of its own but there are various methods to cure concrete which include:
- Surface wetting (ponding or sprinkling)
- Covering the concrete either with wet coverings or plastics
- The application of liquid membranes
- Electrical and infrared curing
- Internal curing
Can You Speed Up Concrete Drying And Curing?
Whilst optimal drying and curing times will result in maximum durability and strength, time may be against you when you are working on projects.
Methods to speed up drying include:
- Using less water in the concrete mix or adding warm water
- Choosing good conditions to pour concrete (not always possible!)
- Using concrete additives that speed up drying or curing
- Avoiding hard trowelling of concrete
- The use of dehumidifiers or heat sources
Because properly curing concrete does take time, it’s much better to plan and take the variability of drying and curing times into account, and then allow some extra time.
SRC Readymix – The Ready Mixed Concrete Experts
We hope you enjoyed our post about concrete drying times and found it helpful.
Remember – purchasing quality ready mixed concrete can also affect drying times. Properly mixed concrete using the correct ratios of high-quality materials is step number one in achieving a successful project.
Our ready mixed concrete is suitable for a wide range of applications and is available for delivery across Essex from one of our four concrete plants.
Don’t hesitate to get in touch with us to discuss your concrete requirements. You can call us on 0208 594 0169 or email us at email@example.com
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