What Problems likely to occur if concrete has too low a slump?

Answer 1

Too much water in the concrete mix results in ultimate weakness in the cured concrete because the extra water takes up space. When the extra water dries out in the course of a few days, there is nothing in the mix that can take its place, so the concrete is slightly sponge-like.

Too much water in the mix can also cause too much cement paste to rise to the surface during finishing, resulting in later plate spalling from the freeze-thaw cycle.

If there is really too much water, the mix may be thin enough to run downhill and not stay in the forms in, say, a sidewalk pour.

It takes little water to allow concrete to chemically cure to full rated strength. Many structural jobs are placed with 2" or even 1-1/2" slump. Of course, the exposed surface will be ultimately weak unless measure are taken to keep it wet during the curing period.

Answer 2

If concrete has too low a slump, it can lead to difficulties in placing and consolidating the concrete properly. This can result in inadequate flowability, making it challenging to mold or shape the concrete into the desired form. It may also increase the chances of segregation and a lack of uniform distribution of aggregates within the concrete mix, potentially compromising the strength and durability of the final hardened concrete.

Answer 3

A low slump indicates too much water in the concrete. A mix with excess water will result in a weakness of the cured concrete.