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

When the slump of concrete is equal to or less than 40 mm, the consolidation method typically used is rodding. Rodding involves using a straight, pointed rod to manually compact the concrete, ensuring that air pockets are eliminated and the mix is homogeneous. This method is particularly effective for low-slump concrete as it helps to ensure that the material is adequately compacted without the risk of overworking the mix, which can lead to segregation or loss of workability.

The other methods, such as shaking, vacuuming, and tapping, are better suited for different consistencies of concrete. Shaking usually applies to mixes with higher slumps where a vibrating action can further facilitate settling. Vacuuming tends to be used in situations where excess water or air needs to be removed from freshly placed concrete, while tapping might refer to minimally influencing a mix with higher fluidity rather than consolidating a low-slump material effectively. Thus, rodding is the most appropriate and effective method for consolidating concrete with a slump of 40 mm or less.