How Does Hot Water Affect Concrete

Spring is here, which means that the dog days of summer are close at hand.? So now is a good time to start thinking about how you’re going to deal with your concrete on those brutally hot days. Concrete and heat make a really bad combination. Not only do the excessive temperatures present safety hazards for contractors, but they also tend to have negative impacts on the concrete itself.?

How does hot weather affect fresh concrete?

One of the main ways that hot, dry temperatures can impact a fresh batch of concrete is by speeding up the setting process.? This presents challenges from the moment the concrete is batched to the time it arrives at the job site to the moment the finishers start working on it.? Concrete that sets up early in hot weather is among the more costly problems the industry faces due to rejected loads and damage to equipment.? Fresh concrete can also lose slump and air concrete due to high temperatures.?

Why does hot weather affect concrete this way?

Concrete sets up through a chemical process known as hydration. When water mixes with cement, a reaction occurs between the molecules.? This reaction generates a significant amount of heat, which produces calcium crystals.? The calcium crystals are what give the concrete its hard structure. Unfortunately, the excess heat from summer temperatures also causes the calcium crystals to form, making the concrete set up faster.??

Can the concrete be slowed down?

The good news is that placing concrete in the warmer months of the year is not impossible, thanks to admixture technology. Delayed Set admixtures are specially formulated to help slow down, or in some cases temporarily stop the hydration process. This can help ensure the concrete arrives at the job site still fresh and provides adequate time for placement and finishing.??

A Word of Caution

Some common practices in the industry may help slow down the concrete, but may also damage it.? One such practice is adding sugar to the load.? Sugar does act as a set delay, but if you add even a just tiny bit too much, it may stop the concrete from setting up completely.? This creates significant problems when it comes time to finish the concrete, and it most likely means the concrete will have to be torn out and replaced.?

Learn More

You can learn more about Fritz-Pak’s Set Delay Admixtures online at fritzpak.com.? Don’t forget to follow our social media channels for more information about how our products can improve your concrete.