Canadian Council of Independent Laboratories (CCIL) Practice Exam 2025 – All-in-One Comprehensive Guide to Exam Success!

In the context of a slump test, readings should be made to the nearest 5mm. This level of precision is sufficient to accurately assess the workability of concrete while also taking into account the practical aspects of typical field conditions. The slump test aims to provide a straightforward measure of how much concrete can flow or settle under its own weight, and a 5mm increment allows for a balance between precision and ease of measurement.

While larger increments, such as 10mm, may offer less detailed information, measuring to the nearest 1mm or 2mm could be unnecessarily precise for the typical variances observed during the slump test. Concrete workability assessments generally do not require such a high level of accuracy, therefore, the 5mm standard is widely accepted in practice. This approach ensures that the results remain both practical and applicable in real-world scenarios without introducing excessive complexity into the measurement process.