ACI Concrete Field Testing Technician - Grade I Practice Exam

The maximum elapsed time allowed between obtaining the final portion of the composite sample and beginning the tests for slump, temperature, and air content is _____ minutes.

1. 1

2. 3

3. 5

4. 10

The correct answer is: 5

The maximum elapsed time allowed between obtaining the final portion of the composite sample and beginning the tests for slump, temperature, and air content is five minutes. This timeframe is crucial because it helps ensure the accuracy and reliability of the test results. If testing is delayed beyond this period, factors such as evaporation, settling of aggregates, and changes in the concrete’s workability can significantly alter the concrete's properties, leading to misleading results. Maintaining the integrity of the sample during this time is essential for effective quality control and compliance with industry standards. By adhering to this five-minute guideline, technicians can provide a more accurate representation of the concrete's characteristics at the time of sampling, which is vital for assessing the material's performance in construction projects.