ACI Certification Practice Exam

If the air content value is read at 5.0% on a pressure air meter, what is the adjusted air content when the correction factor is 0.2%?

1. 5.2%

2. 4.8%

3. 5.0%

4. 6.0%

The correct answer is: 4.8%

To determine the adjusted air content when using a pressure air meter, it is essential to apply the correction factor to the initially measured air content value. In this scenario, the measured air content is 5.0%, and the correction factor is 0.2%. To find the adjusted air content, you subtract the correction factor from the measured value. The calculation proceeds as follows: Adjusted Air Content = Measured Air Content - Correction Factor Adjusted Air Content = 5.0% - 0.2% This yields an adjusted air content of 4.8%. The reason this is correct lies in how pressure air meters operate. They typically require adjustments to account for environmental and operational factors that can influence the accuracy of the air content reading. By applying the correction factor properly, one arrives at the most accurate representation of the air content in the concrete mix, thereby ensuring that the properties of the mix align with desired specifications for strength and durability.