Canadian Council of Independent Laboratories (CCIL) Practice Exam 2026 – All-in-One Comprehensive Guide to Exam Success!

Managing the filling of concrete in a mould exceeding 200mm in height is crucial for ensuring the integrity and strength of the final product. The correct choice suggests filling in three equal lifts, which is a method that helps to minimize issues such as segregation and air entrapment that can occur with larger pours.

When concrete is poured in a single lift or even in two equal lifts for heights exceeding 200mm, the risk of problems increases. A single lift can lead to issues with compaction and create a weak interface if the concrete at the bottom begins to harden before the top layers are added. While two lifts may help reduce the height of the pour, it is still not optimal for heights over 200mm.

By dividing the pour into three equal lifts, each layer can be properly consolidated and allowed to properly bond with the layer beneath it. This method ensures that any air pockets are reduced, and each lift has time to achieve better bonding surfaces. Moreover, this approach can enhance the overall performance of the concrete, affecting its durability and reducing the likelihood of cracking.

Utilizing a vibrating machine throughout the process is a useful tool that aids in compaction, but it does not replace the need for careful lift management. While vibration can assist in reducing