Increasing the slump of concrete has what effect?

• A. Increases its wetness
• B. Increases its strength
• C. Decreases setting time
• D. Reduces workability

Answer: (A)

Slump measures how wet or fluid fresh concrete is. When slump increases, there’s more water relative to cement and aggregates, so the mix becomes wetter and more flowable. That’s why increasing the slump increases its wetness.

In practice, higher slump does raise workability (ease of placement and finishing), but it can also reduce strength and durability due to a higher water–cement ratio. The other options don’t fit: more water doesn’t increase strength, slump isn’t a direct indicator of shorter setting time, and higher slump does not reduce workability—it actually makes the mix more workable.