Red Seal Concrete Finisher Practice Exam

How can you determine if a concrete mix is too dry?

1. It has an uneven texture

2. It crumbles easily and doesn’t hold form

3. It appears too glossy

4. It takes longer to set

The correct answer is: It crumbles easily and doesn’t hold form

When assessing if a concrete mix is too dry, recognizing that it crumbles easily and doesn’t hold form is crucial. A proper concrete mix should maintain its shape and strength after being poured and formed. If the mix is too dry, there is insufficient water to activate the cement particles and create the necessary chemical reaction for hardening, which results in a brittle consistency that crumbles under pressure. This lack of cohesiveness indicates that the mix cannot adequately bond together, leading to a failure to maintain structural integrity. On the other hand, while an uneven texture can indicate issues with mixing or placement, it does not specifically point to the mix being too dry. An overly glossy appearance typically suggests excess moisture or improper finishing techniques, rather than dryness. Similarly, taking longer to set can be a result of many factors, including temperature or humidity, rather than solely an indicator of the mix being too dry. Therefore, the key indicator is the inability of the concrete to hold its form, clearly demonstrating that it lacks sufficient moisture.