ACI Certification Practice Exam

Is it true that additional concrete must be added before the 25th stroke while rodding the top layer of concrete?

1. True

2. False

3. N/A

4. Depends on circumstances

The correct answer is: True

The statement is true because when rodding a concrete mix, the goal is to ensure proper consolidation of the concrete, especially during the placement of the top layer. During this process, if the top layer is not adequately consolidated before the 25th stroke of the rod, there is a likelihood that air pockets or voids may remain in the concrete, which can compromise the integrity of the finished product. To achieve optimal density and minimize porosity, additional concrete is typically added during this phase of rodding if required. This practice is essential for ensuring that the mix is well-distributed and that it adheres to industry standards for strength and durability. Consolidation is crucial, and early intervention with additional material helps to ensure the final structure meets the necessary performance criteria. In contexts where the mix has not yet reached a sufficient density, the addition of concrete prior to the completion of the rodding process becomes a necessary step to maintain quality and performance characteristics.