Canadian Council of Independent Laboratories (CCIL) Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

The correct choice identifies that the minimum height requirement for an internal vibrator should be 50mm less than the specimen height. This standard is established to ensure that the vibrator penetrates deeply enough into the concrete without encountering limitations that could hinder its efficiency during compaction.

By specifying a depth that is proportionate to the specimen's size, this guideline helps promote optimal results in consolidating the mixture, minimizing air pockets, and achieving the uniformity required for structural integrity. Ensuring the vibrator's height is adequately lower than the specimen helps maximize vibration distribution throughout the concrete, enhancing its performance characteristics.

Understanding the rationale behind this requirement is vital for maintaining quality standards in laboratory practices and construction applications.