Naturally, concrete needs some ample time to cure and set well after pouring. Construction sites in hot, dry and windy weather always have a hard time pouring their concrete well especially if they cannot wait for the temperatures to dip.
In concrete pouring lingo, anything above 33 degrees Celsius (90 degrees Fahrenheit) is hot weather for concrete. Above this temperature, your concrete slab or column’s integrity is at risk no matter how well you used the concrete reinforcing mesh.
So what happens when you pour concrete in hot weather and how can you mitigate these negatives?
Hot, Dry, Windy Weather Affects Hydration
Hydration is the process concrete employs to dry and set. The process needs water; hence this is the reason curing cement is occasionally doused with water. High temperatures increase the hydration process. This coupled with the fact that hot, dry and windy weather evaporates water on the surface leaves the concrete with little or no water for proper hydration and curing.
This, therefore, means that the biggest issue isn’t the air temperature. It is the rate at which the water evaporates from the concrete surface and the slab’s internal temperature that affects the rate of hydration.
Effects of Pouring Concrete in Hot Weather
- It’s harder to finish the concrete.
- Formation of cold joints due to decreased setting time.
- Lowered durability and strength.
- The concrete shrinks more upon drying.
- Higher chances of cracking.
How to Pour Concrete Well in Hot Weather
If you are anticipating hot pours and cannot avoid them in any way, you can use the following tricks to better the quality of concrete your pour. Remember that waiting for the coolest hours of the hot weather will always tip the odds in your favor.
- Get more workers to finish up the concrete as soon as it is poured.
- Use sunshades and windbreaks to control airflow over the concrete.
- Use ice or cold water as part of the mix to cool the concrete.
- Spray cold water onto the concrete after pouring to keep it cold and hydrated.
- Ensure that the concrete is put to use as soon as it is mixed.
Get Your Logistics in Place Before Pouring
Some steps used in keeping the concrete within the acceptable temperatures can be adverse. For instance, mega projects that need concrete at its best can even use liquid nitrogen to cool down the concrete before pouring it. If you are going for extra steps, even if they are menial, such as using cold water to cool things down, ensure that you have it close at hand before starting the pour.
Concrete is the main construction material of our era. Despite its versatility and reliability, it can easily be the bane in any construction if not let to cure and set well.
Understanding the structural integrity you expect of your construction will help you choose the right measures for pouring the concrete or even decide if it is wise to pour at night and give the concrete a head start before the sun starts heating things up.