What effect does increasing the slump of concrete have?

Increasing the slump of concrete is associated with a greater wetness or fluidity in the mix, which allows for easier placement and workability. A higher slump indicates that the concrete is more workable and has a higher water content, which makes it easier to mold and finish. This increased wetness can help in achieving a smoother finish and ensuring that the concrete fills forms and corners effectively.

While the other choices touch on important attributes of concrete, they relate more to specific aspects of durability, strength, or dimensional stability, rather than the immediate effect of increased slump, which directly correlates with the workability and fluidity of the concrete mix. Higher water content can sometimes lead to other issues if not managed properly, but fundamentally, a higher slump means a wetter, more workable concrete mix at the outset.