Chemicals added to concrete mixtures during cold weather conditions modify the hydration process, allowing cement to cure properly despite low temperatures. These admixtures typically accelerate the hardening process, generate heat to offset the cold, or lower the freezing point of water within the mix. For instance, calcium chloride is a common accelerating admixture.
Protecting concrete from freezing during its early stages is critical for achieving desired strength and durability. Without proper protection or the use of these specialized admixtures, concrete placed in cold weather can experience delayed setting, reduced strength gain, and increased susceptibility to freeze-thaw damage, ultimately compromising the structural integrity. Historically, protecting concrete during cold weather involved laborious and costly methods like heated enclosures and blankets. The development of these specialized chemical admixtures revolutionized cold-weather concreting by offering a more efficient and cost-effective solution.