ACI Concrete Field Testing Technician - Grade I Practice Exam

How should field cured cylinders be protected during the curing process?

1. With a plastic covering

2. In the same way as the formed work

3. In a heated chamber

4. By placing them in insulated boxes

The correct answer is: In the same way as the formed work

Field cured cylinders should be protected during the curing process in the same way as the formed work. This approach ensures that the curing environment for the cylinders mimics the conditions experienced by the concrete in place. Proper protection maintains moisture and temperature levels, which are essential for achieving the specified strength and durability of the concrete. When field cured cylinders are treated similarly to the formed concrete, it helps to prevent issues like drying out or temperature fluctuations that could adversely affect the hydration process of the cement paste. Factors such as moisture retention and consistent temperature are critical to allow the concrete to gain strength effectively. Alternative methods, such as covering with plastic or placing in heated chambers, may not replicate the conditions of the formed work accurately and could lead to discrepancies in the strength results when compared to the actual concrete placement. Insulated boxes could maintain temperature, but unless they also address moisture retention and mimic in-situ conditions, they may not provide the best method for curing field cylinders.