Standard Test Methods for Minimum Index Density and Unit Weight of Soils and Calculation of Relative Density
|Publication Date:||1 March 2016|
|ICS Code (Earthworks. Excavations. Foundation construction. Underground works):||93.020|
These test methods cover the determination of the minimum-index dry density/unit weight of cohesionless, freedraining soils. The adjective "dry" before density or unit weight is omitted in the title and remaining portions of this standards to be be consistent with the applicable definitions given in Section 3 on Terminology.
System of Units:
The testing apparatus described in this standard has been developed and manufactured using values in the gravimetric or inch-pound system. Therefore, test apparatus dimensions and mass given in inch-pound units are regarded as the standard.
It is common practice in the engineering profession to concurrently use pounds to represent both a unit of mass (lbm) and a unit 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. This test method has been written using the gravitational system of units when dealing with the inch-pound system. In this system, the pound (lbf) represents a unit of force (weight). However, balances or scales measure mass; and weight must be calculated. In the inch-pound system, it is common to assume that 1 lbf is equal to 1 lbm. While reporting density is not regarded as nonconformance with this standard, unit weights should be calculated and reported since the results may be used to determine force or stress.
The terms density and unit weight are often used interchangeably. Density is mass per unit volume, whereas unit weight is force per unit volume. In this standard, density is given only in SI units. After the density has been determined, the unit weight is calculated in SI or inch-pound units, or both.
Three alternative methods are provided to determine the minimum index density/unit weight, as follows:
Method A-Using a funnel pouring device or a hand scoop to place material in mold.
Method B-Depositing material into a mold by extracting a soil filled tube.
Method C 2-Depositing material by inverting a graduated cylinder.
The method to be used should be specified by the agency requesting the test. If no method is specified, the provisions of Method A shall govern. Test Method A is the preferred procedure for determining minimum index density/ unit weight as used in conjunction with the procedures of Test Methods D4253. Methods B and C are provided for guidance of testing used in conjunction with special studies, especially where there is not enough material available to use a 0.100 ft3 (2830 cm3) or 0.500 ft3 (14 200 cm3) mold as required by Method A.
These test methods are applicable to soils that may contain up to 15 %, by dry mass, of soil particles passing a No. 200 (75-μm) sieve, provided they still have cohesionless, free-draining characteristics (nominal sieve dimensions are in accordance with Specification E11).
Method A is applicable to soils in which 100 %, by dry mass, of soil particles pass a 3-in. (75-mm) sieve and which may contain up to 30 %, by dry mass, of soil particles retained on a 1½-inch (37.5-mm) sieve.
Method B is applicable to soils in which 100 %, by dry mass, of soil particles pass a 3⁄4-inch (19.0-mm) sieve.
Method C is applicable only to fine and medium sands in which 100 %, by dry mass, of soil particles pass a 3⁄8-in. (9.5-mm) sieve and which may contain up to 10 %, by dry mass, of soil particles retained on a No. 10 (2.00-mm) sieve.
Soils, for the purposes of these test methods, shall be regarded as naturally occurring cohesionless soils, processed particles, or composites or mixtures of natural soils, or mixtures of natural and processed particles, provided they are free-draining
All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.
For purposes of comparing a measured or calculated value(s) to specified limits, the measured or calculated value(s) shall be rounded to the nearest decimal or significant digits in the specified limits.
The procedures used to specify how data are collected/ recorded or calculated in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user's objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analysis methods for engineering design.
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.
2 Kolbuszewski, J. J., "An Experimental Study of the Maximum and Minimum Porosities of Sands," Proceedings, Second International Conference on Soil Mechanics and Foundation Engineering, Rotterdam Vol I, 1948, pp. 158-165.
*A Summary of Changes section appears at the end of this standard