When it comes to concrete, there are few variables that need to be considered like that of the outside temperature. And while it is best to pour concrete when temperatures are above 10 degrees Celsius, the weather does not always cooperate. If the external temperature is too low, then special considerations need to be taken to ensure that the concrete hardens properly. Here is some information on pouring concrete in cold weather.
The American Concrete Institute has determined that concrete poured at temperatures below 5 degrees Celsius be deemed “cold weather” concrete. In addition to this, according to the ACI, the air temperature must remain below 10 degrees Celsius for half of one 24-hour period of time. If these criteria are met, then the application will be considered “cold weather”.
There are a handful of techniques that can be implemented to get concrete to set up properly in cold weather, and one of the foremost is through the use of insulated blankets, also known as curing blankets. Insulated blankets are padded coverings that are laid over the surface of freshly poured concrete to help keep it warm, thus dramatically decreasing curing times. In addition, these blankets can help to maintain moisture throughout the hydration process. Best of all, insulated blankets are easy to use and install.
An efficient way to ensure that concrete hardens properly in cold weather is by introducing additives into the mixture. Additives work by increasing the rate at which the hydration process takes place. This rate increase then helps the concrete to set more rapidly. There are a variety of additive types that are specially designed for cold weather concrete applications, such as accelerators and superplasticizers.
Heating and Hoarding
There is another well-known method for speeding up concrete curing times in cold weather – heating and hoarding. Essentially, heating and hoarding is completed by placing plastic over the poured concrete, while at the same time using a portable heater to add warmth to the area. Before trying this method, check to make sure that the heater you are using is safe for heating and hoarding purposes.
Cold Weather Concrete
Pouring concrete in cold weather undoubtedly presents its own set of obstacles. However, with the correct techniques problems can be avoided. If you are going to be pouring concrete in cold weather you will definitely want to consider using an insulated blanket. In addition, concrete additives can help speed up the curing process so that the concrete will harden more rapidly. Lastly, you may want to try using the “heating and hoarding” method to keep the concrete warm while it sets. Take heed to this advice when pouring concrete in cold weather and the project should go off without a hitch.