Which procedure describes the Modified Proctor Test?

The Modified Proctor Test is an essential procedure used to determine the optimal moisture content and maximum dry density of soil for compaction purposes. It is specifically conducted using a 10-pound hammer dropped from a height of 18 inches. This method is designed to simulate the conditions that soil would experience in actual compaction scenarios, allowing engineers and construction professionals to achieve the proper level of soil density for stability and support in construction projects.

The use of a 10-pound hammer and the specified drop height are critical because they provide a standardized way to assess the soil’s response to compaction efforts. This standardization ensures that results are consistent and can be relied upon when deciding how much compaction effort needs to be applied in a given project.

The other options relate to different methods or components that do not define the Modified Proctor Test specifically. For instance, a 5-pound hammer dropped from a height of 12 inches refers to the Standard Proctor Test, which uses different parameters to measure soil compaction. Utilizing a vibrating plate compactor and incorporating water content measurement are important concepts in soil testing and compaction but are not the defining features of the Modified Proctor Test process itself.