If you get a collapse slump in a slump test for concrete, it can be because of
- AVery wet mix
- BFlowable concrete
- CSegregation
- DAny of theseCorrect
Solution
Concept
A collapse slump signifies a harsh, highly fluid, or segregated mix where the concrete loses its shape entirely, making it unsuitable for standard slump measurement.
Step-by-step solution
1. Understand the slump test as a measure of concrete workability. 2. Identify the types of slumps: true slump, shear slump, and collapse slump. 3. Recognize that a collapse slump occurs when the concrete completely loses its shape and spreads out. 4. Connect this condition to a very wet mix, high flowability, or segregation of aggregates.
Explanation
A collapse slump indicates that the concrete is extremely wet, highly flowable, or suffering from segregation, meaning it lacks cohesiveness and spreads out completely. Therefore, any of these conditions can lead to a collapse slump in the standard slump cone test.
Why the other options are wrong
A: A very wet mix causes collapse, but so do flowable concrete and segregation. B: Flowable concrete can also result in a collapse slump. C: Segregation causes loss of uniformity and leads to a collapse slump.
Shortcut
Collapse always means the mix is too wet, highly flowable, or segregated.
Common mistake
Assuming a collapse slump only represents a high water-cement ratio, ignoring segregation or extreme flowability.
Correct answer: D) Any of these