What specifications must a rammer meet for a Modified Proctor test?

The specification for a rammer used in the Modified Proctor test is that it must free fall from a height of 18 inches and have a weight of 10 pounds. This standard is established to ensure that the compaction of soil is consistent and replicable, allowing for accurate assessment of its properties.

In the context of the Modified Proctor test, it is crucial to use a rammer that meets these specific specifications because they are designed to apply a consistent amount of energy to the soil sample. The height from which the rammer falls directly influences the energy imparted to the soil during the compaction process, which in turn affects the density and moisture relationship of the soil. The specified weight of 10 pounds is also critical, as it ensures that the force exerted during each blow is sufficient to achieve the desired level of compaction.

Other options do not align with the recognized standards for the Modified Proctor test, which defines the parameters necessary for achieving reliable and valid results.