1、Designation: D7830/D7830M 13D7830/D7830M 14Standard Test Method forIn-Place Density (Unit Weight) and Water Content of SoilUsing an Electromagnetic Soil Density Gauge1This standard is issued under the fixed designation D7830/D7830M; the number immediately following the designation indicates theyear
2、of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope Scope*1.1 This test method covers the procedures for determ
3、ining in-place properties of non-frozen, unbound soil and soil aggregatemixtures such as total density, gravimetric water content and relative compaction by measuring the electromagneticintrinsicimpedance of the compacted soil.1.1.1 The method and device described in this test method are intended fo
4、r in-process quality control of earthwork projects. Siteor material characterization is not an intended result.1.2 UnitsThe values stated in either SI units or inch-pound units given in brackets are to be regarded separately as standard.The values stated in each system may not be exact equivalents;
5、therefore, each system shall be used independently of the other.Combining values from the two systems may result in non-conformance with the standard.1.2.1 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 for
6、ce (weight) while the unit for mass is slugs. The rationalized slug unit is not given in this standard.1.2.2 In the engineering profession, it is customary practice to use, interchangeably, units representing both mass and force,unless dynamic calculations are involved. This implicitly combines two
7、separate systems of units, that is, the absolute system andthe gravimetric system. It is undesirable to combine the use of two separate systems within a single standard. The use of balancesor scales recording pounds of mass (lbm), or the recording of density in lbm/ft3 should not be regarded as nonc
8、onformance withthis standard.1.3 All observed and calculated values shall conform to the Guide for Significant Digits and Rounding established in PracticeD6026.1.3.1 The procedures used to specify how data is collected, recorded, and calculated in this standard are regarded as industrystandard. In a
9、ddition, they are representative of the significant digits that should generally be retained. The procedures used do notconsider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the users objectives;and it is common practice to increase or decrea
10、se the number of significant digits of reported data commensurate with theseconsiderations. It is beyond the scope of this standard to consider significant digits used in the analysis methods for engineeringdesign.1.4 This standard does not purport to address all of the safety concerns, if any, asso
11、ciated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.NOTE 1ASTM International takes no position respecting the validity of any patent rights asserted in con
12、nection with any item mentioned in thisstandard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of suchrights, are entirely their own responsibility.2. Referenced Documents2.1 ASTM Standards:2D422 Test Method fo
13、r Particle-Size Analysis of SoilsD653 Terminology Relating to Soil, Rock, and Contained FluidsD698 Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (12 400 ft-lbf/ft3 (600 kN-m/m3)1 This test method is under the jurisdiction ofASTM Committee D18 on Soil and Rock a
14、nd is the direct responsibility of Subcommittee D18.08 on Special and ConstructionControl Tests.Current edition approved Feb. 1, 2013. Published April 2013November 2014. DOI: 10.1520/D7830-13.Originally approved in 2013. Last previous edition approved in2013 as D7830 13. DOI:10.1520/D7830_D7830M14.2
15、 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to
16、provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof
17、the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D1556 Test Method for Density and Unit Weight
18、 of Soil in Place by Sand-Cone MethodD1557 Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft3 (2,700kN-m/m3)D2167 Test Method for Density and Unit Weight of Soil in Place by the Rubber Balloon MethodD2216 Test Methods for Laboratory Determination
19、of Water (Moisture) Content of Soil and Rock by MassD2937 Test Method for Density of Soil in Place by the Drive-Cylinder MethodD3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used inEngineering Design and ConstructionD4253 Test Methods fo
20、r Maximum Index Density and Unit Weight of Soils Using a Vibratory TableD4254 Test Methods for Minimum Index Density and Unit Weight of Soils and Calculation of Relative DensityD4318 Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of SoilsD4643 Test Method for Determination of Wat
21、er (Moisture) Content of Soil by Microwave Oven HeatingD4718 Practice for Correction of Unit Weight and Water Content for Soils Containing Oversize ParticlesD7382 Test Methods for Determination of Maximum Dry Unit Weight and Water Content Range for Effective Compaction ofGranular Soils Using a Vibra
22、ting HammerD4944 Test Method for Field Determination of Water (Moisture) Content of Soil by the Calcium Carbide Gas Pressure TesterD4959 Test Method for Determination of Water (Moisture) Content of Soil By Direct HeatingD6026 Practice for Using Significant Digits in Geotechnical DataD6938 Test Metho
23、d for In-Place Density and Water Content of Soil and Soil-Aggregate by Nuclear Methods (Shallow Depth)E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method2.2 Other Referenced Documents:“Development of a Non-Nuclear Soil Density Gauge to Eliminate the Need
24、 for Nuclear Density Gauges”33. Terminology3.1 DefinitionsDefinitions:3.1.1 See Terminology D653 for general definitions.3.2 Definitions of Terms Specific to This Standard:3.2.1 impedance, na measure of opposition to alternating current (AC).3.2.2 impedance spectroscopy, na method that measures the
25、electromagnetic properties of a medium as a function offrequency.4. Summary of Test Method4.1 The total or wet density and gravimetric water content of soil and soil-aggregate are correlated to empirical data using anelectromagnetic impedance spectroscopy device. Electromagnetic properties of the so
26、il are determined at specific frequencies bymeasuring the changes in the electromagnetic field. A function is generated that describes the relationship between electricalproperties over a range of frequencies. That function is compared to an empirical model and other calibration checks to determinew
27、ater content and density.4.2 This method employs electromagnetic impedance spectroscopy to determine the volumetric water content and wet density.The measurement spectrum is made up of frequencies ranging from 30 kHz to 50 MHz.4.3 Properties such as dry density, gravimetric water content and relativ
28、e compaction are calculated from the total density andthe volumetric water content.5. Significance and Use5.1 The method described determines wet density and gravimetric water content by correlating complex impedancemeasurement data to an empirically developed model. The empirical model is generated
29、 by comparing the electrical properties oftypical soils encountered in civil construction projects to their wet densities and gravimetric water contents determined by otheraccepted methods.5.2 The test method described is useful as a rapid, non-destructive technique for determining the in-place tota
30、l density andgravimetric water content of soil and soil-aggregate mixtures and the determination of dry density.5.3 This method may be used for quality control and acceptance of compacted soil and soil-aggregate mixtures as used inconstruction and also for research and development. The non-destructi
31、ve nature allows for repetitive measurements at a single testlocation and statistical analysis of the results.NOTE 2The quality of the result produced by this standard test method is dependent on the competence of the personnel performing it, and the3 Prepared for The Department of Homeland Security
32、 under contract No. HSHQDC-07-C-00080. Dated October 31, 2008. Available from the U.S. Department ofHomeland Security, Washington, D.C. 20528, http:/www.dhs.gov.D7830/D7830M 142suitability of the equipment and facilities used. Agencies that meet the requirements of Practice D3740 are generally consi
33、dered capable of competentand objective sampling/testing/inspection, and the like. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assurereliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluation some of those
34、factors.6. Interferences6.1 Anomalies in the test material with electrical impedance properties significantly different from construction soils andaggregate evaluated during soil model development, such as metal objects or organic material, may affect the accuracy of the testmethod.6.2 Chemical and
35、mineralogical composition may affect the results of a test. Examples of materials that may impact the resultsinclude but are not limited to, quarried materials containing higher concentrations of iron, volcanic rock, and materials that havesignificant fractions of cemented particles, organic soils,
36、recycled materials or materials containing asphalt, portland cement, lime,fly ash, or other stabilizing modifiers. In most cases the effect may be satisfactorily addressed by following the CalibrationProcedure in Section 7.6.3 A significant increase in the conductivity of the pore water such as from
37、 ground water that may contain significant saltdeposits or contaminants. In most cases the effect may be satisfactorily addressed by following the Calibration Procedure in Section7.6.4 This test method applies only to non-frozen soil. The electrical properties of soil change with temperature. Genera
38、lly, testingshould be limited to soil temperatures above 10C 50F and below 40C 104F. Effects of temperature on electrical propertiesof soils also depend on soil type. Clayey soils are more temperature sensitive than sandy soils.Accuracy of measurements improveswhen the temperature of soil is close t
39、o the temperature used in the model calibration. Calibration for temperature effects shouldbe done when soil temperatures differ by more than 10C 18F from model calibration temperatures. Calibration Procedures aregiven in Section 7.6.5 The accuracy of the results obtained by this test method may be
40、influenced by poor or incorrect placement of the deviceon the soil being tested. Non-homogeneous soils, non-uniform surface texture, large air voids that may be present may decreasethe precision of the results. Correct placement of the soil gauge is important to the quality of the electrical measure
41、ments collectedby the device.6.6 Oversized particles in the measurement volume may cause an error in water content and/or density results. Where lack ofuniformity in the soil is suspected due to layering, aggregates, or voids, the test site should be excavated and visually examinedto determine if th
42、e material is representative of the in-situ material in general and if an oversize correction is required in accordancewith Practice D4718.6.7 Variation from actual values may increase for soil material that is significantly drier or wetter than optimum water contentas determined using Test Methods
43、D698 or D1557. Variation from actual values may increase for soil material that is compactedto less than 80 % of the maximum dry density as determined using Test Methods D698 or D1557.6.8 Attempts to measure unknown in-place soils with a soil model that was generated from a limited range of wet dens
44、ity orwater content values, or both, may result in density and water content errors.6.9 Strong electromagnetic fields such as those generated by high tension power lines may interfere with the device operation.6.10 For a circular sensor 280 mm 11 in. in diameter, the typical maximum measured volume
45、is approximately 0.0034 m30.12 ft3.The actual measured volume is indeterminate and varies with the plate diameter, sensor configuration, and material beingtested. Results are typically influenced more by the density and water content of the material near the surface.7. Apparatus4,57.1 Electromagneti
46、c Soil Density GaugeA device capable of generating an electromagnetic field and measuring thedifferential voltage change between two electrodes. An example of the device is shown in Fig. 1 and a sensor schematic sectionand approximate electrical fields that sense the soil is shown in Fig. 2. While t
47、he exact details of construction of the apparatus mayvary, the system shall consist of:7.1.1 Electronic circuitry to provide power and signal conditioning to the sensor and to provide the data acquisition and displayfunctions. The circuitry shall be designed to perform a calibration of the unit over
48、 a range of conditions and materials expectedin the field.7.1.2 Internal circuitry suitable for displaying individual measurements to allow operators to record the results.4 The sole source of supply of the TransTech Soil Density Gauge (SDG) apparatus known to the committee at this time is TransTech
49、 Systems, Inc. 1594 State Street,Schenectady, NY. If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive carefulconsideration at a meeting of the responsible technical committee, which you may attend.5 The Electromagnetic Soil Density Gauge is covered by a patent (patent no.: US 7,219,024 B2). Interested parties are invited to submit information regarding theidentification of an alternative(s) to this patented item to the ASTM International Headquarters. Your comments w
