What is the slump of the concrete if the measured height is 178 mm?

To determine the slump of concrete, it is essential to understand the method used for measuring slump, which typically involves the use of a standardized slump cone apparatus. When a slump cone is filled with concrete and subsequently lifted, the amount by which the concrete settles (or slumps) is measured as the difference in height from the original height of the concrete in the cone to the final height after the cone is removed.

In this case, if the measured height after the cone is lifted is 178 mm, this specifically indicates how far the concrete has slumped from its initial mold height, which is conventionally higher than the final measurement. If 178 mm is interpreted as the total height after the slump, it means that's the remaining height after some settlement has occurred.

To ascertain the specific slump height, additional context is needed regarding the original height of the concrete column when placed in the cone. However, assuming that the reference for comparison and measurement is a standard initial height of 305 mm, the slump can then be calculated by subtracting the measured height from this typical height.

Thus, the slump would be calculated as follows:

305 mm (initial height) - 178 mm (measured height post-slump) = 127 mm.

Therefore