ACI Concrete Field Testing Technician - Grade I Practice Exam

What is the recommended action to protect a concrete sample from contamination?

1. Rapid evaporation

2. Use of a protective cover

3. Immediate transportation to a lab

4. Avoid mixing with other samples

The correct answer is: Rapid evaporation

The recommended action to protect a concrete sample from contamination is the use of a protective cover. When concrete samples are left exposed, they can be susceptible to various forms of contamination, such as dirt, debris, moisture, or chemicals from the environment. A protective cover helps create a barrier that prevents these pollutants from interacting with the sample, ensuring that the integrity and properties of the concrete are maintained until testing can occur. Utilizing a protective cover is particularly crucial during the transportation of samples, as it helps shield them from elements that could compromise the results. Techniques like rapid evaporation are not designed specifically for contamination prevention and could inadvertently lead to changes in moisture content or the concrete's properties. Immediate transportation to a lab is important for timely testing but does not directly address contamination during the sample's initial handling. Likewise, while avoiding mixing samples is a good practice, it does not provide the same level of protection from external contaminants as a protective cover does.