Massachusetts Construction Supervisor License (CSL) Practice Test

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

1. A. Fine aggregate

2. B. Re-bar

3. C. Cement

4. D. Sand

The correct answer is: B. Re-bar

In a concrete mix, the primary ingredients typically include fine aggregate, cement, and sand. These components combine chemically and physically to form concrete, which is a fundamental material used in construction for its durability and strength. Fine aggregate, such as sand, is essential as it provides volume and contributes to the strength and stability of the concrete. Cement acts as the binding agent that holds all the aggregates together. Sand, while often classified under fine aggregate, plays a critical role in creating the necessary workability and consistency of the mix. Re-bar, on the other hand, is not an ingredient of the concrete mix itself; rather, it is a reinforcing material that is added to enhance the tensile strength of the concrete in structural applications. While re-bar is crucial in concrete construction, it is used primarily for reinforcement purposes and does not constitute a component of the concrete mixture. Understanding the distinct roles of these materials is vital for anyone involved in construction, as it informs proper mixing ratios and reinforces the structural integrity of the projects undertaken.