ACI Concrete Field Testing Technician - Grade I Practice Exam

Is a composite sample of concrete needed if the only purpose is to determine temperature?

1. True

2. False

3. Only in large volumes

4. Only if specified by the engineer

The correct answer is: False

The determination of the temperature of concrete does not necessitate the collection of a composite sample. A single temperature reading can adequately reflect the concrete's state at the time of testing, rendering the need for a composite sample unnecessary. Temperature is typically measured using a thermometer inserted into the fresh concrete, allowing for an immediate and accurate reading without the need to aggregate samples from various sections of the pour, as would be done for other tests like slump or compressive strength. In situations where the main focus is solely on temperature, composite sampling—where samples are taken from different locations and mixed together—is not relevant. This is because temperature fluctuations can be measured directly and do not require the averaging effect of multiple samples, as is necessary for more comprehensive assessments of the concrete's properties.