ACI Concrete Field Testing Technician - Grade I Practice Exam

How much time is allowed to conduct the slump test from beginning to completion?

1. 1 minute

2. 2 minutes

3. 2 1/2 minutes

4. 3 minutes

The correct answer is: 2 1/2 minutes

The slump test is a critical procedure used to measure the consistency and workability of fresh concrete. According to industry standards, the entire process of conducting the slump test—from obtaining the concrete sample to measuring the slump—should ideally be completed within 2.5 minutes. This time constraint is important because concrete can begin to set shortly after mixing; therefore, delays might affect the accuracy of the slump measurement. Maintaining this timeline ensures that the test reflects the concrete's behavior as it is during mixing rather than after any initial setting has started. The procedure involves filling the slump cone with concrete, leveling the top, removing the cone, and then measuring how far the concrete has slumped. By completing this within the specified time frame, the technician can achieve a reliable and relevant measurement for evaluating the concrete's properties at that moment. Overall, adhering to this time limit is essential for obtaining valid results in accordance with the guidelines established by standards such as ASTM C143.