It’s not surprising that concrete is affected by temperature.

But it might surprise you how much of an effect it can have.

Hot weather is tough on concrete workers. They have to deal with a variety of factors that are working against them in their quest to create a pristine slab.

Temperature’s effect on concrete

Concrete has a fairly narrow temperature band where it’s optimal to work with, and outside of that band you have to start adjusting the mix and doing other things that can make it set better. In cold weather you have to decrease water, keep the ground thawed, put blankets or heaters on the pour site or other solutions designed to keep heat in the wet concrete.

But in hot weather, you have to do something a little different.

Hot weather makes concrete dry faster. That sounds good, but usually isn’t. if concrete dries out too fast it’s vulnerable to cracking and has a lower tensile strength. It can crack as it dries, but also after it’s mostly dried out. Think of your hands when the weather outside is really dry. Just like your skin, concrete needs moisture.

The mixture is also less plastic and workable than it usually would be. That means the concrete can harden up too fast, or not be able to get the kind of smooth finish that a good pour will have. It’s not optimal.

Solutions for concrete pours in hot weather

More water in the mix will help, but it lowers the strength because it means there’s less of the cement and aggregate that actually makes up concrete when the water evaporates away.

Covering the concrete to keep the sun and wind off is a good solution if the job site allows for it. Pouring at a different time of day can help. In hot climates, concrete workers often get started very early to get ahead of the sun. Humidity of the surrounding area also helps.

And hiring or bringing more workers is a good solution for the problem of workability. More workers means less area for each to cover, which means even if it’s a little harder for them to get the right finish they have the extra hands to get it done.

If you want a consistent concrete result in any temperature you have to hire a contractor that knows what they’re doing. Contact JKI today. We’ll help you get the best concrete pour possible for your project.