ACI Certification Practice Exam

What should be done to ensure the integrity of testing concrete samples?

1. Store in a hot environment

2. Prevent contamination and evaporation

3. Use larger aggregate

4. Mix continuously

The correct answer is: Prevent contamination and evaporation

To ensure the integrity of testing concrete samples, preventing contamination and evaporation is essential. Maintaining the quality and accuracy of concrete samples during the testing phase is critical for reliable results. Contamination can occur through various sources, such as dust, foreign materials, or even moisture from the environment, which can alter the properties of the concrete mix. This alteration can lead to inaccurate test results, which could misinform decisions regarding material quality, structural integrity, or design specifications. Similarly, evaporation can affect the moisture content of the concrete sample, leading to premature hardening or changes in the sample's workability. This impacts tests that are sensitive to water-to-cement ratios or other aspects of the mix. By focusing on keeping the samples protected from contamination and monitoring environmental conditions to minimize evaporation, the reliability of the testing process is greatly enhanced, resulting in more accurate assessment of the concrete's performance characteristics.