Fig. 1: Proctor Mould & Rammer
Metal mould (volume = 1000 cm^{3} for 100 mm diameter mould and volume= 2250 cm^{3} for 150 mm diameter mould & Metal rammer conforming to IS: 9189-1979. (weight = 4.9 kg)
To obtain the graphical relationship of the “dry density’ to “moisture content” in the form of “compaction curve’, for determining the values of Optimum Moisture Content (OMC) and Maximum Dry Density (MDD).
Metal mould (volume = 1000 cm^{3} for 100 mm diameter mould and volume= 2250 cm^{3} for 150 mm diameter mould & Metal rammer conforming to IS: 9189-1979. (weight = 4.9 kg)
The balance to be used must be sensitive to the extent of 0.1% of total weight of sample taken
IS-2720 (Part-8):1983 (Reaffirmed- May 2015) “Methods of test for soils: Determination of water content - dry density relation using heavy compaction”.
The dry densities, γ_{d}, obtained in a series of determinations is plotted against
the corresponding moisture content ‘M’. A smooth curve is then drawn through
the resulting points and the position of the maximum on this curve is determined,
which is called maximum dry density (M.D.D). And the corresponding moisture content
is called optimum moisture content (O.M.C.).
Fig. 3 : Plot of dry Unit Weight v/s Moisture Content (Compaction Curve)