North Carolina Building Contractor License Practice Exam

No masonry shall be supported on what specified condition?

1. Slump between 5 and 10 in

2. Slump between 8 and 11 in

3. Slump between 11 and 15 in

4. Slump between 2 and 5 in

The correct answer is: Slump between 8 and 11 in

In masonry construction, slump refers to the consistency or fluidity of fresh concrete and is measured by the degree to which a concrete cone slumps when tested. Maintaining an appropriate slump is critical for both the workability and durability of the concrete. The specified condition that masonry should not be supported on relates to a slump that indicates it is too wet and may not achieve the necessary strength or bonding required for structural integrity. When the slump is too high, particularly in the range of 8 to 11 inches, the concrete may become overly fluid, leading to segregation of materials within the mix and insufficient compaction around reinforcement. This can compromise the overall performance of the masonry structure, leading to issues such as cracking or failure. In contrast, slump levels that are lower, such as those indicated by the other choices, tend to indicate that the concrete has better cohesiveness and workability. These values generally support the structural performance and the intended design criteria for masonry applications. Therefore, the condition specifying a slump between 8 and 11 inches is the critical threshold where masonry should not be supported, ensuring the longevity and strength of the structure.