soils having maximum particle sizes of approximately 11¤2 in. (38 mm) and test hole volumes of approximately 0.1 ft3 (2830 cm3). When the material being tested contains a small amount of oversize and isolated larger particles are encountered, the test should be moved to a new location. Larger apparatus and test hole volumes are needed when particles larger than 11¤2 in. (38 mm) are prevalent. The apparatus described here represents a design that has proven satisfactory. Larger apparatus, or other designs of similar proportions may be used as long as the basic principles of the sand volume determination are observed. When test hole volumes larger than 0.1 ft3 (5660 cm3) are required Test Method D 4914 should be utilized.
6.2 SandÐSand must be clean, dry, uniform in density and grading, uncemented, durable, and free-¯owing. Any gradation may be used that has a uniformity coefficient (Cu 5 D60/D10) less than 2.0, a maximum particle size smaller than 2.0 mm (No. 10 sieve), and less than 3 % by weight passing 250 µm (No. 60 sieve). Uniformly graded sand is needed to prevent segregation during handling, storage, and use. Sand free of ®nes and ®ne sand particles is required to prevent signi®cant bulk-density changes with normal daily changes in atmo-spheric humidity. Sand comprised of durable, natural sub-rounded, or rounded particles is desirable. Crushed sand or sand having angular particles may not be free-¯owing, a condition that can cause bridging resulting in inaccurate density determinations (see Note 3). In selecting a sand from a potential source, a gradation and bulk-density determinations in accordance with the procedure in Annex A2 should be made on each container or bag of sand. To be an acceptable sand, the bulk-density variation between any one determination shall not be greater than 1 % of the average. Before using sand in density determinations, it shall be dried, then allowed to reach an air-dried state in the general location where it is to be used (see Note 4). Sand shall not be re-used without removing any contaminating soil, checking the gradation, drying and rede-termining the bulk-density (see Note 5). Bulk-density tests of the sand will be made at time intervals not exceeding 14 days, always after any signi®cant changes in atmospheric humidity, before reusing, and before use of a new batch from a previously approved supplier (see Note 6).
NOTE 3ÐSome manufactured (crushed) sands such as blasting sand have been successfully used with good reproducibility. The reproducibility of test results using angular sand should be checked under laboratory controlled testing situations before selecting an angular sand for use.
NOTE 4ÐMany organizations have found it bene®cial to store sands in moisture resistant containers. Sand should be stored in dry areas protected from weather. The use of a lighted bulb or other heat source in, or adjacent to the storage containers has also been found to be bene®cial in areas of high humidity.
NOTE 5ÐAs a general rule, reclaiming sand after testing is not desirable.
NOTE 6ÐMost sands have a tendency to absorb moisture from the atmosphere. A very small amount of absorbed moisture can make a substantial change in bulk-density. In areas of high humidity, or where the humidity changes frequently, the bulk-density may need to be determined more often than the 14 day maximum interval indicated. The need for more frequent checks can be determined by comparing the results of different bulk-density tests on the same sand made in the same conditions of use over a period of time.
6.3 Balances or ScalesÐMeeting Speci®cation D 4753,
3
with 5.0 g readability, or better, to determine the mass of sand and excavated soils. A balance or scale having a minimum capacity of 20 kg and 5.0-g readability is suitable for deter-mining the mass of the sand and the excavated soil when apparatus with the dimensions shown in Fig. 1 is used.
6.4 Drying EquipmentÐEquipment corresponding to the method used for determining water content as speci®ed in Test Methods D 2216, D 4643, D 4959, or D 4944.
6.5 Miscellaneous EquipmentÐKnife, small pick, chisel, small trowel, screwdriver, or spoons for digging test holes, large nails or spikes for securing the base plate; buckets with lids, plastic-lined cloth sacks, or other suitable containers for retaining the density samples, moisture sample, and density sand respectively; small paint brush, calculator, notebook or test forms, etc.
7. Procedure
7.1 Select a location/elevation that is representative of the area to be tested, and determine the density of the soil in-place as follows:
7.1.1 Inspect the cone apparatus for damage, free rotation of the valve, and properly matched baseplate. Fill the cone container with conditioned sand for which the bulk-density has been determined in accordance with Annex A2, and determine the total mass.
7.1.2 Prepare the surface of the location to be tested so that it is a level plane. The base plate may be used as a tool for striking off the surface to a smooth level plane.
7.1.3 Seat the base plate on the plane surface, making sure there is contact with the ground surface around the edge of the ¯anged center hole. Mark the outline of the base plate to check for movement during the test, and if needed, secure the plate against movement using nails pushed into the soil adjacent to the edge of the plate, or by other means, without disturbing the soil to be tested.
7.1.4 In soils where leveling is not successful, or surface voids remain, the volume horizontally bounded by the funnel, plate and ground surface must be determined by a preliminary test. Fill the space with sand from the apparatus, determine the mass of sand used to ®ll the space, re®ll the apparatus, and determine a new initial mass of apparatus and sand before proceeding with the test. After this measurement is completed, carefully brush the sand from the prepared surface (see Note 7).
NOTE 7ÐA second calibrated apparatus may be taken to the ®eld when this condition is anticipated (instead of re®lling and making a second determination). The procedure in 7.1.4 may be used for each test when the best possible accuracy is desired, however, it is usually not needed for most production testing where a relatively smooth surface is obtainable.
7.1.5 The test hole volume will depend on the anticipated maximum particle size in the soil to be tested. Test hole volumes are to be as large as practical to minimize the errors and shall not be less than the volumes indicated in Table 1. A hole depth should be selected that will provide a representative sample of the soil. For construction control, the depth of the hole should approximate the thickness of one, or more, compacted lift(s). The procedure for calibrating the sand must re¯ect this hole depth. See Annex A2.
7.1.6 Dig the test hole through the center hole in the base