1. Scope

1.1 This test method outlines procedures for determining the water (moisture) content of soil by chemical reaction using calcium carbide as a reagent to react with the available water in the soil producing a gas. A measurement is made of the gas pressure produced when a specified mass of wet or moist soil is placed in a testing device with an appropriate volume of reagent and mixed.

1.2 This test method is not intended as a replacement for Test Method D2216; but as a supplement when rapid results are required, when testing is done in field locations, or where an oven is not practical for use. Test Method D2216 is to be used as the test method to compare for accuracy checks and correction.

1.3 This test method is applicable for most soils. Calcium carbide, used as a reagent, reacts with water as it is mixed with the soil by shaking and agitating with the aid of steel balls in the apparatus. To produce accurate results, the reagent must react with all the water which is not chemically hydrated with soil minerals or compounds in the soil. Some highly plastic clay soils or other soils not friable enough to break up may not produce representative results because some of the water may be trapped inside soil clods or clumps which cannot come in contact with the reagent. There may be some soils containing certain compounds or chemicals that will react unpredictably with the reagent and give erroneous results. Any such problem will become evident as calibration or check tests with Test Method D2216 are made. Some soils containing compounds or minerals that dehydrate with heat (such as gypsum) which are to have special temperature control with Test Method D2216 may not be affected (dehydrated) in this test method.

1.4 This test method is limited to using calcium carbide moisture test equipment made for 20 g, or larger, soil specimens and to testing soil which contains particles no larger than the No. 4 Standard sieve size.

1.5 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems 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. For specific hazards statements, see Section 7.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

D653 Terminology Relating to Soil, Rock, and Contained Fluids

D2216 Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass

D3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction

D4753 Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction Materials Testing

D6026 Practice for Using Significant Digits in Geotechnical Data

E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves

E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods

E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method

Keywords

acceptance test; calcium carbide; gas pressure; moisture content; pressure-measuring instrument; quick test; soil moisture; soil water content; water content

ICS Code

ICS Number Code 13.080.40 (Hydrological properties of soil)

DOI: 10.1520/D4944-98

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