Значение и использование

These tests determine the optimum water content and maximum density (unit weight) to be used for molding soil-cement specimens in accordance with Methods D 559 and D 560.

Note 1—Since these tests are used in conjunction with Methods D 559 and D 560 and the criteria referenced therein, the test differs in several aspects from Test Methods D 698. There are three main differences between this standard and Test Method D 698. Firstly, this standard allows a maximum particle size of ¾-in. (19.0 mm) for a 4-in. (101.6-mm) mold while D 698 allows a maximum particle size of ³/₈-in. (9.5-mm) for the same size mold. Secondly, this standard permits the material leftover after the water content specimen has been obtained to be mixed with the rest of the sample and reused for the next determination. Test Method D 698 does not permit the material to be reused. Thirdly, this standard allows the material that is retained on the ¾-in. (19.0-mm) and passing the 3-in. (75-mm) to be discarded (scalping technique) and replaced with an equal mass of material that passes the ¾-in. (19.0-mm) sieve and is retained on the No.4 (4.75-mm) sieve. Test Method D 698 does not permit the scalp and replacement technique.

Note 2—The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D 3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D 3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D 3740 provides a means of evaluating some of those factors.

Область применения

1.1 These test methods cover the determination of the relationship between the water content and the density of soil-cement mixtures when compacted before cement hydration as prescribed.

1.2 A 1/30-ft³ (944-cm³) mold and a 5.5-lb (2.49-kg) rammer dropped from a height of 12.0 in. (30.5 cm) are used and two methods, depending on soil gradation, are covered, as follows:

SectionsTest Method A, using soil material passing a No. 4 (4.75-mm) sieve.This method shall be used when 100 % of the soil sample passes the No. 4 (4.75-mm) sieve7Test Method B, using soil material passing a 3/4-in. (19.0-mm) sieve.This method shall be used when part of the soil sample is retained on the No. 4 (4.75-mm) sieve. This test method may be used only on materials with 30 % or less retained on the 3/4-in. (19.0-mm) sieve8

1.3 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D 6026.

1.4 The values stated in inch-pound units are to be regarded as the standard, except as noted below. The values given in parentheses are mathematical conversions to SI units, and are provided for information only and are not considered standard.

1.4.1 The gravitational system of inch-pound units is used when dealing with inch-pound units. In this system, the pound (lbf) represents a unit of force (weight), while the unit for mass is slugs.

1.4.2 The slug unit of mass is almost never used in commercial practice (density, scales, balances, etc.). Therefore, the standard unit for mass in this standard is either kilogram (kg) or gram (g) or both. Also, the equivalent inch-pound unit (slug) is not given.

1.4.3 It is common practice in the engineering/construction profession to concurrently use pounds to represent both a unit of mass (lbm) and of force (lbf). This implicitly combines two separate systems of units; that is, the absolute system and the gravitational system. It is scientifically undesirable to combine the use of two separate sets of inch-pound units within a single standard. As stated in 1.4.2, this standard includes the gravitational system of inch-pound units and does not use/present the slug unit for mass. However, the use of balances or scales recording pounds of mass (lbm) or recording density in lbm/ft³ shall not be regarded as nonconformance with this standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.