North Carolina Building Contractor License Practice Exam

High-early strength concrete must be maintained at how many degrees in moist conditions for 3 days?

1. 40

2. 50

3. 60

4. 70

The correct answer is: 50

High-early strength concrete typically needs to be cured in moist conditions at an optimal temperature range to achieve its desired strength within a short duration. Maintaining the concrete at 50 degrees Fahrenheit for the first three days allows for adequate hydration and proper curing, which are critical to developing the early strength needed in high-early strength concrete formulations. Curing at this temperature supports the exothermic hydration process of the cement, ensuring that the chemical reactions occur effectively without risking cold joints or the negative impacts of freezing conditions. The specified curing temperature helps prevent too rapid drying and ensures that the concrete retains moisture, further assisting in developing the necessary strength. Following the recommended curing practices is essential for high-early strength concrete, especially in construction projects that demand quick turnaround times, as the benefits of high early strength can be crucial in speeding up construction schedules.