Cold Weather Concrete Placement requires which guidance?

• A. Use heated enclosures for curing.
• B. Do not place below 40 degrees Fahrenheit.
• C. Apply chemical accelerating admixtures in every mix.
• D. Do not place below 50 degrees Fahrenheit.

Answer: (B)

Cold weather placement hinges on ensuring concrete temperature stays high enough for proper hydration and strength gain. The guidance is to not place concrete when the temperature falls to or below 40°F, because below this level hydration slows, microcracking can occur, and early strength development is compromised. Protective measures like heated enclosures, insulated blankets, or other warming methods can be used to allow placement in cooler conditions, but they are ways to work around low temperatures—not a blanket requirement in every case. The other options misstate the baseline: relying on chemical accelerators in every mix isn’t a universal rule, and setting a higher minimum like 50°F isn’t the standard practice.