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

The correct answer is based on the specified requirements for the curing duration of cylinders in laboratory settings, particularly for concrete testing. Curing is a critical process that allows the material to hydrate properly, ensuring the integrity and strength of the final product.

The specified duration of "28 +/- 8 hours" is centered on industry standards that allow for some flexibility in timing based on environmental conditions. This range (20 to 36 hours total) accommodates variations such as temperature and humidity, which can affect the curing process. The 28-hour mark is typically a standard reference point for many concrete curing and testing protocols because it allows for sufficient hydration, ensuring the cylinders develop the appropriate compressive strength during subsequent testing.

Other options suggest different time frames that may not align with best practices or might extend the curing period unnecessarily, which could lead to complications in testing and evaluation. In essence, the 28-hour duration supports optimal conditions for accurate results while aligning with established guidelines in the field of concrete testing.