Red Seal Concrete Finisher Practice Exam

What is the primary function of a concrete vibrator?

1. To remove moisture from concrete

2. To ensure proper mixing of ingredients

3. To eliminate air pockets and improve compaction

4. To assist in finishing the surface

The correct answer is: To eliminate air pockets and improve compaction

The primary function of a concrete vibrator is to eliminate air pockets and improve compaction within the poured concrete. When concrete is mixed and poured, it can contain air bubbles and pockets that may weaken the final structure if not addressed. The use of a concrete vibrator helps to settle the concrete and allow it to flow more freely, effectively displacing trapped air. This process ensures that the concrete achieves a more uniform density, enhances the bond between aggregates, and ultimately leads to a stronger, more durable surface once it has cured. Improved compaction is crucial in applications where strength and stability are necessary, such as in driveways, foundations, and structural slabs. The reduction of air pockets minimizes the likelihood of cracking and other structural weaknesses, leading to better overall performance of the concrete.