Canadian Council of Independent Laboratories (CCIL) Practice Exam

In the context of the slump flow test, "maximum spread" refers to the largest area the material can cover after the cone used in the test is removed. This measurement is crucial as it provides insights into the workability and flow characteristics of the concrete mix being evaluated. A greater maximum spread indicates that the concrete is more fluid and can move more easily, which is often desirable in applications requiring high workability. The other choices do not align with the definition of maximum spread. The minimum height the cone can be lifted pertains to different aspects of the test rather than the spread of the material. The time taken for the material to settle is related to how quickly it flows, but does not define its maximal coverage. Lastly, the total weight of the sample used does not influence the spread; it is a separate characteristic of the concrete mix that may affect other properties but is not directly related to the spread observed in this test.