General information
Principle
It is observed that, if a certain type of soil is compacted with a certain amount of energy, the obtained dry density ρd of the compacted soil initially increases with the water content w. However, from a certain water content, a decrease in the density of the compacted soil is found.
Thus, in a diagram ρd/w the obtained curve must exhibit a maximum: the 'optimal water content' wopt for a maximum density ρd,max.
We will always apply the standard compaction in the lab.
There is also a modified or strengthened Proctor compaction with more energy, it yields different values for wopt and ρd.