1、Designation:D438012Standard Test Method forDensity of Bentonitic Slurries1This standard is issued under the fixed designation D4380;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses ind
2、icates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the densityof slurries used in slurry construction techniques,such as thoseused for barriers to control the horizontal
3、movement of liquids.This test method is modified from API Recommended Prac-tice 13B.1.2 UnitsThe values stated in SI units are to be regardedas standard,unless other units are also specified,such asdensity in lbm/ft3or lbm/gal.No other units of measurementare included in this standard.1.3 This stand
4、ard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM S
5、tandards:2D653 Terminology Relating to Soil,Rock,and ContainedFluidsD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and Construction2.2 American Petroleum Institute(API)Standard:API RP 13B Recommended Practice Sta
6、ndard Procedure forTesting Drilling Fluids(Section 1)33.Terminology3.1 Definitions:3.1.1 For definitions of terms relating to this test method,refer to Terminology D653.4.Summary of Test Method4.1 The mud balance is the instrument generally used forthis test method.The weight of a fixed volume of th
7、e slurry ismeasured by moving a rider counterweight along a graduatedscale.The density of the slurry is then read directly off thegraduated scale after the instrument is balanced.5.Significance and Use5.1 This test method is used to determine the density ofbentonitic slurries in the laboratory and f
8、ield.For freshly mixedslurry,this test method may be used as an indicator of mixproportions.For in-trench slurry,a certain value may bespecified for maintaining trench stability.NOTE1The quality of the result produced by this standard depends onthe competence of the personnel performing it and the s
9、uitability of theequipment and facilities being used.Agencies that meet the criteria ofPractice D3740 are generally considered capable of competent andobjective testing,sampling,inspection,etc.Users of this standard arecautioned that compliance with Practice D3740 does not in itself ensurereliable r
10、esults.Reliable results depend on many factors;Practice D3740provides a means of evaluating some of those factors.6.Apparatus6.1 Mud BalanceAny instrument of sufficient accuracy topermit measurement within 60.01 g/cm3may be used,however,the mud balance is the instrument generally used(seeFig.1).The
11、mud balance consists of a mud cup attached to oneend of a beam which is balanced on the other end by a fixedcounterweight and a rider free to move along a graduated scale.A level bubble is mounted on the beam.Attachments forextending the range of the balance may be used.7.Calibration7.1 The instrume
12、nt should be calibrated frequently withfresh water.Fresh water should give a reading of 1.00 g/cm3at20 C.If it does not,adjust the balancing screw or the amountof lead shot in the well at the end of the graduated arm asrequired.8.Procedure8.1 Set up the instrument base approximately level.8.2 Fill t
13、he clean,dry cup with slurry to be tested,place thecap on the cup,and rotate the cap until firmly seated.Makesure some of the slurry is expelled through the hole in the capto free trapped air or gas.1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct re
14、sponsibility of Subcommittee D18.04 on HydrologicProperties and Hydraulic Barriers.Current edition approved Aug.1,2012.Published November 2012.Originallyapproved in 1984.Last previous edition approved in 2006 as D438084(2006).DOI:10.1520/D4380-12.2For referenced ASTM standards,visit the ASTM website
15、,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from theAmerican Petroleum Institute,2101 L St.,NW,Washington,DC 20037.Copyright ASTM International,100 Barr
16、 Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 8.3 Wash or wipe the excess slurry from the outside of thecup.8.4 Place the beam on the support and balance it by movingthe rider along the graduated scale.The beam is horizontalwhen the leveling bubble is on the center line.8.5 Read the density at the side of the rider toward the knifeedge.Make appropriate corrections when a range extender isused.8.6 Record the density to the nearest 0.01 g/cm3.8.7 Clean and dry the instru
