Madison Concrete Construction worked in cold weather conditions on Lincoln Financial Field
Working with concrete in cold weather presents challenges. However, understanding best practices for doing so can help ensure the concrete quality and strength is not compromised. There are two main problems with working with concrete in cold weather: it can freeze before it gains strength, which breaks up the matrix, and concrete sets more slowly when it is cold.
When the concrete temperatures is less than 50 degrees Fahrenheit, concrete sets very slowly. When the concrete temperature is less than 40 degrees Fahrenheit, the hydration essentially ceases and the concrete can’t gain strength. Once the concrete has reached about 500 psi compressive strength, it can handle the cold – the cement hydration has consumed enough of the water in the original mix so if it does freeze, there isn’t enough water left in the pores to damage the concrete. Until this strength is achieved, the concrete needs to be protected.
Concrete temperature can be checked by using an infrared temperature gun or using maturity methods. Two methods include changing the mix so it sets more quickly and protecting the concrete from the cold. Many of the issues that affect concrete in cold weather can be overcome by the ready-mix producer. If admixtures are added at the jobsite, don’t use them if they have frozen because the chemicals may have separated. In many applications, air-entrained concrete –which uses a chemical admixture to produce a system of small voids during the mixing process – is used for freeze-thaw resistance. These voids are stabilized by the air-entraining admixture and remain in the hardened concrete paste.
Madison constructed 585,000-sq. ft. of structural reinforced concrete on two levels throughout a seven-month period for the Lincoln Field Stadium Project. We placed more than 25,000 cu. yds. in a variety of conditions, including pouring concrete in very hot weather and very cold weather. We’d like to hear about the projects you’ve worked on and how we may use our experience to work with you.