soil compactors are used to perform test methods which cover laboratory compaction methods used to determine the relationship between molding water content and dry unit weight of soils. soil placed as engineering fill is compacted to a dense state to obtain satisfactory engineering properties such as, shear strength, compressibility, or permeability. in addition, foundation soils are often compacted to improve their engineering properties. laboratory compaction tests provide the basis for determining the percent compaction and molding water content needed to achieve the required engineering properties, and for controlling construction to assure that the required compaction and water contents are achieved. test methods such as en 13286-2, en 13286-47, astm d698, astm d1557, aashto t99, aashto t180, aashto t193, bs 1377:4 provide soil compaction testing procedures.