ACI Certification Practice Exam

What preparation is needed before making tests with fresh concrete?

1. Use concrete that is at room temperature

2. Plasticize the concrete

3. Break down large aggregates

4. Ensure proper sample transportation

The correct answer is: Break down large aggregates

Before making tests with fresh concrete, proper preparation is essential to ensure the accuracy and reliability of the test results. One important aspect of this preparation is to ensure that the sample is handled appropriately during collection and transportation. Proper sample transportation is crucial because the properties of fresh concrete can change rapidly once it is mixed. Factors such as temperature, exposure to air, and agitation can all affect the results of subsequent tests. By ensuring that the concrete sample is transported correctly—such as by avoiding delays, keeping it at a consistent temperature, and protecting it from contaminants—you can maintain its integrity for accurate testing. The other options, while they may pertain to concrete testing, do not address the key concern of maintaining the concrete's properties during the critical period before testing. Using concrete that is at room temperature might not be relevant in some circumstances, and breaking down large aggregates could alter the nature of the concrete being tested, leading to potentially erroneous results. Plasticizing the concrete may modify its workability, but it does not directly relate to the necessary preparation for ensuring test accuracy prior to conducting tests. Thus, focusing on proper sample transportation is vital for achieving valid and reliable outcomes when testing fresh concrete.