When special concrete mixtures are created in the batching process and extra precautions are taken at the job site, your winter concrete pour can go smoothly.
””Winter projects can present certain challenges when it comes time to pour concrete for foundations, slabs, and other surfaces. However, pouring concrete in cold weather is a common practice for a reason. When you have a job to do, you cannot always afford to wait on the weather to cooperate. When we make some adjustments in the mixing process and you take the necessary precautions for the pour, then you should be able to successfully complete your project.
The Problem with Cold Weather
Adjustments must be made to the pouring process when the temperature is going to drop below 40°F. This is because the curing process can become more difficult the closer the temperature gets to freezing. Most importantly, the concrete should never be allowed to freeze because this can crack the material and further reduce its strength and durability. This is why techniques have been developed to combat these issues, both in how we mix the concrete and how you care for it while it is curing.
Mixing for Cold Weather
There are a number of things that can be done to fight cold temperatures while creating the concrete mixture. Some of the tactics include:
- Mix designs. Various chemical accelerators and air-entrainment admixtures can be added to speed up the curing time of the concrete and resist the effects of freeze-thaw conditions. The additives used will depend on the situation, as certain chemicals can have disadvantages. Calcium chloride mixtures, for example, do not mix well with metal wire mesh or rebar used for reinforcement because they can cause steel to corrode which can later lead to cracking.
- Additional cement. Additional cement can be added to the mix to speed up curing time.
- Hot water. The concrete mixture can be prepared with hot water to keep the mixture nice and warm as it travels to the work site. The temperature of the water needs to be consistent across batches, however, to ensure equal performance.
Pouring Concrete in Cold Weather
Preparing the right concrete mixture is only half the battle when you are pouring concrete in cold weather. You still need to keep the concrete and the ground it is placed on warm enough to cure properly after it has been poured. This can be accomplished using a variety of methods:
- Thawing the ground. Concrete should never be poured on frozen ground. If you pour on frozen ground, your concrete is likely to crack once the ground thaws and settles. Instead, the ground should be close to the temperature of the concrete being poured. This can be accomplished by laying down hot gravel or sand, covering the ground with insulation for several days, or steaming the ground.
- Cover with a curing blanket. Concrete actually emits heat as it cures, something you can take advantage of to maintain its temperature. Use specialized curing blankets placed on top of the concrete to keep this heat in and protect the concrete from freezing.
- Curing compounds. Various curing compounds can be applied with a sprayer to aid in curing the concrete. Keep in mind that compounds can perform differently, depending on their composition. Some are designed to cure and seal, while others are solvent-based. We can help you choose the right compound for your project based on the weather conditions and the mix we are supplying for you.
If you are preparing to pour concrete in cold weather for an upcoming project, contact the team at Razorback Concrete or call 870-455-0700 for immediate assistance. Our ready-mix concrete professionals have the experience and know-how to help ensure your concrete pour goes smoothly this winter.