Massachusetts Unrestricted Construction Supervisor License Practice Test

Which of the following is NOT an ingredient of a concrete mix?

1. Fine aggregate

2. Sand

3. Cement

4. Re-bar

The correct answer is: Re-bar

In a concrete mix, the primary ingredients typically include cement, fine aggregate (which is usually sand), and coarse aggregate. The purpose of these ingredients is to form a composite material where the cement acts as a binder that hardens and holds the aggregates together. Re-bar, or reinforcing bar, is not actually an ingredient in the concrete mix itself. Rather, it is an additional material that is used to strengthen the concrete structure. It is placed within the concrete before it sets to provide tensile strength, helping to resist cracking and structural failure, especially in tension zones. While re-bar is essential for many types of concrete construction, particularly in structural applications, it does not constitute a fundamental component of the concrete mix itself. Therefore, it is correctly identified as not being an ingredient of the concrete mix.