Concrete curing is a critical process within any home renovation or commercial development project, playing a hand in determining the overall strength, durability and appearance of the concrete used. As a result of this, understanding the do’s and don’ts of concrete curing is essential for achieving the best results possible for your builds. In this article, we will delve into what concrete curing actually is, as well as looking into how long the process takes and most importantly, what essential practices and pitfalls there are which you must navigate. Ultimately, this blog will equip you with knowledge of the concrete curing process, so that your builds can really stand the test of time.
What is Concrete Curing?
The terms concrete curing and concrete drying are often used interchangeably. However, the correct name for the process is concrete curing, since concrete doesn’t actually dry. As a process, curing the concrete refers to the chemical reaction that sees your fresh poured concrete mixture undergo a hardening and setting process. As your water, cement and aggregated mixture begins to bind together, proper curing will ensure the subsequent mixture to attain its full strength and durability. So at its core, curing will see your wet concrete solidify into a solid, long-lasting construction material which you can then use as part of foundations, driveways, retaining walls and more.
How Long Does Concrete Take to Cure?
There is no set or pre-determined amount of time it takes concrete to cure. As you would imagine, the length of time required for your concrete to properly cure will inevitably vary depending on a wide range of factors including the type of cement used, the quality of the cement, the volume of cement poured, weather and climate conditions, the potential application of the concrete and much more.
In an ideal scenario, the longer you leave your concrete mixture to cure the better, as this will allow it to set uninterrupted and reach its full strength. The issue with this is that this could take days, weeks, months or even years in some cases, and you’ve probably poured your concrete with an intention of actually getting some use out of it.
In fact, the Hoover Dam, which is constructed of three and one quarter million cubic yards of concrete is still undergoing the curing process to this day. After construction of the Hoover Dam completed all the way back in 1936, it was estimated that the concrete used would require over 100 years to cure completely using conventional methods. This means to this day, the concrete is still hardening over time. Of course, it is unlikely that your project is going to be the same scale and require the same volume of concrete as the Hoover dam, therefore as a general rule of thumb, it is accepted that your concrete will achieve around 70% of its specified strength within 7 days, and approximately 90% after around 28 days.
Concrete Curing – What to Do
BEGIN THE CURING PROCESS AS SOON AS POSSIBLE
As stated previously, the concrete curing process is dependent on a chemical reaction taking place without interruption. To do so it requires ample moisture, which is present in abundance immediately after concrete is poured. So by leaving your concrete to cure as soon as it has been laid, you are ensuring your mixture can cure with as much moisture as the hydration process requires.
CONTROL THE TEMPERATURE AROUND YOUR CONCRETE
Weather conditions and overall climate can have a significant impact on your concrete’s curing process, which is why it is essential that you do your part in at least somewhat regulating its temperature. Extreme hot conditions will lead to rapid water evaporation which will impact the curing process, whilst colder temperatures will impede the process from actually occurring, reducing the strength of your mixture. Concrete blankets are used to help with temperature regulation and ensure concrete slabs cure properly.
EMPLOY CURING COMPOUNDS AND ADMIXTURES
Whilst the curing process will occur naturally, strengthening your concrete over time, various curing compounds and admixtures can be used to promote the hydration process. The purpose of these compounds is to form a membrane on the surface of your freshly-poured concrete which helps to retain moisture. This in turn will support the curing process, preventing moisture loss and the formation of cracks.
Concrete Curing – What to Avoid
USING CONTAMINATED WATER
Water is one of the three essential ingredients in manufacturing high-quality concrete, along with cement and aggregates such as gravel, sand, stone etc. Using impure or contaminated water will have a negative impact on the curing process, compromising the concrete’s properties and long-term performance.
REMOVING COVERS TOO EARLY
It’s best practice to cover your newly-laid concrete with some sort of blanket or sheet in order to prevent the rapid loss of moisture or heat. What isn’t best practice is removing any covers too prematurely as this will suddenly disturb the controlled conditions/ecosystem which the cover was able to create.
PUTTING TOO MUCH WEIGHT ON CONCRETE
Any irritation or disturbance to the surface of your concrete mixture will cause damage and structural weakness. Walking on your concrete or placing heavy weights will inevitably lead to uneven surfaces, imprints or even internal cracks which will reduce the concrete’s load-bearing capacity.
DISRUPTING THE CURING PROCESS ONCE IT HAS STARTED
Adding more water and remixing the concrete once it has started curing disrupts the natural curing process and reduces the final strength of the concrete.
There are numerous do’s and don’ts when it comes to curing concrete, and having the knowledge to know which practice belongs to which can make all the difference in determining the strength of your concrete. From understanding the importance of maintaining consistent moisture to recognising the detrimental effects of extreme temperatures, following the guidelines and recommendations of this article will help pave the way for safer and more resilient structures.
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