AASHTO T 190:14(2018) Standard Method of Test for Resistancel R-Value and Expansion Pressure of Compacted Soils.
5. PREPARATION OF SOIL SPECIMENS
5.1. Thoroughly mix four 1200-g samples of soil with the amount of water estimated to equal one half to two thirds of the water required to produce saturation as defined in Sections 5.3 and 5.4. Place the samples in covered containers and allow them to stand overnight. Just prior to compaction, mix the samples with the final amount of water required to produce saturation. The first sample is used as a pilot specimen to assist in determining the final amount of water required.
5.2. Weigh out enough material to fabricate a compacted sample 101 .6 mm (4 in.) in diameter by
63.5 mm (2.5 in.) high. Compacted specimens having heights from 58.4 to 68.6 mm (2.3 to
2.7 in.) are acceptable. Compact the soil into the mold by means of the kneading compactor as follows: Place the mold in the mold holder that has a rubber disk, 100 mm (3’/,6 in.) in diameter and 3 mm (‘/x in.) thick cemented to the plate. Adjust the mold for approximately 3-mm (‘/x-in.) clearance between the lower edge of the mold and base of the mold holder by placing a shim under the edge of the mold or by tightening the set screw (if available) on the mold holder. With the compactor foot pressure set at 1724 ± 172 kPa (250 ± 25 psi), feed 76.2 mm (3 in.) of the soil in the trough into the mold. Feed the balance of the soil into the mold in 20 equal increments with one application of the ram after each increment. Allow 10 additional tamps to level the soil, then place a rubber disk on top of the specimen. loosen the set screw (if available). and remove the shim from under the mold. Apply 100 additional tamps with a foot pressure of 2413 kPa (350 psi). Stop compacting the soil at any time before 100 lamps if water appears around the bottom of the mold.
Note 1—Use lower compaction pressures when necessary to limit penetration of the ram into the soil to not greater than 6.35 mm (1/4 in.).
5.3. Remove the mold containing the compacted specimen from the compactor. Level the surface by hand tamping with the tamping rod. Place a phosphor-bronze disk on the tamped surface of the soil and place a filter paper on top of the bronze disk. Invert the mold and place it on the exudation-indicator device so the filter paper is on the bottom.AASHTO T 190 pdf download.