1、Designation: D6773 16Standard Test Method forBulk Solids Using Schulze Ring Shear Tester1This standard is issued under the fixed designation D6773; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number
2、 in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the apparatus and proceduresfor measuring the unconfined yield strength of bulk solidsduring both continuous flow an
3、d after storage at rest. Inaddition, measurements of internal friction, bulk density, andwall friction on various wall surfaces are included.1.2 This test method covers operation of the manually-controlled Schulze Ring Shear Tester.An automated version ofthis tester is also available. Its method of
4、testing bulk solids issimilar in principle to that described in this test method.1.3 The most common use of this information is in thedesign of storage bins and hoppers to prevent flow stoppagesdue to arching and ratholing, including the slope and smooth-ness of hopper walls to provide mass flow. Pa
5、rameters forstructural design of such equipment may also be derived fromthis data. Another application is the measurement of theflowability of bulk solids, for example, for comparison ofdifferent products or optimization.1.4 All observed and calculated values shall conform to theguidelines for signi
6、ficant digits and rounding established inPractice D6026.1.4.1 The procedures used to specify how data are collected/recorded or calculated in this standard are regarded as theindustry standard. In addition, they are representative of thesignificant digits that generally should be retained. The proce
7、-dures used do not consider material variation, purpose forobtaining the data, special purpose studies, or any consider-ations for the users objectives: and it is common practice toincrease or reduce significant digits of reported data to becommensurate with these considerations. It is beyond the sc
8、opeof this standard to consider significant digits used in analysismethods for engineering design.1.5 UnitsThe values stated in SI units are to be regardedas standard. No other units of measure are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if a
9、ny, 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 Standards:2D653 Terminology Relating to Soil, Rock, and Cont
10、ainedFluidsD2216 Test Methods for Laboratory Determination of Water(Moisture) Content of Soil and Rock by MassD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4753 Guide for Evaluating, Selecting,
11、and Specifying Bal-ances and Standard Masses for Use in Soil, Rock, andConstruction Materials TestingD6026 Practice for Using Significant Digits in GeotechnicalDataD6128 Test Method for Shear Testing of Bulk Solids Usingthe Jenike Shear Cell3. Terminology3.1 DefinitionsFor common definitions of tech
12、nical termsin this standard, refer to Terminology D653.4. Summary of Test Method4.1 A representative specimen of bulk solid is placed in ashear cell of specific dimensions.4.2 When running an instantaneous or time shear test, anormal load is applied to the cover, and the specimen ispresheared until
13、a steady state shear value has been reached.The shear stress is then immediately reduced to zero.4.3 An instantaneous test is run by shearing the specimenunder a reduced normal load until the shear force goes througha maximum value and then begins to decrease.1This test method is under the jurisdict
14、ion ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.24 on Characterizationand Handling of Powders and Bulk Solids.Current edition approved Feb. 1, 2016. Published March 2016. Originallyapproved in 2002. Last previous edition approved in 2008 as D6773 08. DOI
15、:10.1520/D6773-16.2For referenced ASTM standards, visit the ASTM website, 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.*A Summary of Changes section appears at th
16、e end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.4 A time shear test is run similarly to an instantaneousshear test, except that the specimen is placed in a consolidationbench for the specified time between the
17、preshear and shearsteps.4.5 A wall friction test is run by sliding the specimen overa coupon of wall material and measuring the frictional resis-tance as a function of normal, compressive load.4.6 A wall friction time test involves sliding the specimenover the coupon of wall material, stopping and l
18、eaving the loadon the specimen for a predetermined period, and then sliding itagain to see if the shearing force has changed.5. Significance and Use5.1 Reliable, controlled flow of bulk solids from bins andhoppers is essential in almost every industrial facility.Unfortunately, flow stoppages due to
19、arching and ratholing arecommon. Additional problems include uncontrolled flow(flooding) of powders, segregation of particle mixtures, usablecapacity which is significantly less than design capacity, cakingand spoilage of bulk solids in stagnant zones, and structuralfailures.5.2 By measuring the flo
20、w properties of bulk solids, anddesigning bins and hoppers based on these flow properties,most flow problems can be prevented or eliminated (1).35.3 For bulk solids with a significant percentage of particles(typically, one third or more) finer than about 6 mm (14 in.), theunconfined yield strength i
21、s governed by the fines (6 mmfraction). For such bulk solids, strength and wall friction testsmay be performed on the fine fraction only.NOTE 1The quality of the result produced by this standard isdependent on the competence of personnel performing it, and thesuitability of the equipment and facilit
22、ies used. Agencies that meet thecriteria of Practice D3740 are generally considered capable of competentand objective testing/sampling/inspection/etc. Users of this standard arecautioned that compliance with Practice D3740 does not in itself ensurereliable results. Reliable results depend on many fa
23、ctors; Practice D3740provides a means of evaluating some of those factors. Practice D3740 wasdeveloped for agencies engaged in the testing or inspection (or both) ofsoil and rock. As such it is not totally applicable to agencies performingthis standard. However, users of this standard should recogni
24、ze that theframework of Practice D3740 is appropriate for evaluating the quality ofan agency performing this standard. Currently there is no known quali-fying national authority that inspects agencies that perform this standard.6. Apparatus6.1 The Schulze Ring Shear Tester (Figs. 1-6) is composedof
25、a base 1 and a casing 2. The casing 2 contains the drivingand measuring units and carries the working table 38.6.2 The driving axle 5 (with detachable plastic cap 6) causesthe shear cell 4 to rotate. The driver pins at the underside of theshear cell must set in the toothed wheel at the driving axle
26、5 toenable a close connection between shear cell and driving axle.The driving axle is driven by an electric motor and can rotateto the right or to the left. In order to shear the bulk solidspecimen, the driving axle 5 along with the shear cell 4 rotateclockwise (as seen from the top). The electric m
27、otor iscontrolled from the front panel 35 at the front side of casing 2(Fig. 3). The motor and drive system cause the shear cell torotate at a speed adjustable between 0.007 and 0.13 rad/min.6.3 The shear cell lid 7 as well as the bottom of the shearcell 4 has bent bars made of stainless steel (Fig.
28、 4) to preventslipping of the bulk solid at the lid or the bottom of the shearcell.NOTE 2The standard cell has 20 bars, each of which is 4 mm tall(hMit= 4 mm, Fig. 7).6.4 The crossbeam 8 sits on the lid 7 and is fixed with twoknurled screws 9.The crossbeam 8 has several functions: In thecenter of th
29、e crossbeam 8 is a fixed axis 10 with a hook toappend the hanger 11 (in Figs. 3 and 4 only the handle of thehanger standing out from the driving axle can be seen). Rollersat the ends of the crossbeam and the removable guide rollers 12prevent movement of lid 7 from the centered position.6.5 A hook 14
30、 at the upper end of the axis 10 of thecrossbeam 8 is fastened to the balance arm 15. This arm alongwith counterbalance 29 (Fig. 6) serves to compensate for themasses of lid 7, crossbeam 8, hanger 11, and tie rods 13. Thecounterbalance 29 is found at the rear side of the balance arm15.6.6 A digital
31、displacement indicator 31 (Fig. 8) is used forthe measurement of the height of the bulk solid specimen.6.7 Bolts at the ends of the crossbeam 8 are used to appendthe tie rods 13. Therefore, a circular hole is at one end of eachtie rod 13. The opposite end is provided with an elongated holefor suspen
32、ding in the adjustable seating 16 attached to the loadbeam 17.6.8 The rotation of the lid 7 is prevented by the tie rods 13which transfer the tensile force to the load beams 17.6.9 The bottom part of the hanger 11, which hangs on thecrossbeam 8 and serves for exerting a normal load N on thebulk soli
33、d, is located within the base 1 (Fig. 1). The hanger hasa circular plate 19 at its lower end for holding the applied masspieces.6.10 For control of the motor drive a front panel 35 (Fig. 3)is at the front side of the casing 2.6.11 The load beams 17 are connected parallel. Each loadbeam should be cap
34、able of measuring a force up to 200 N witha precision of 0.02 % of full scale. Thus, the total measuringrange, which is twice the measuring range of one load beam, is400 N. The signal from the force transducer is conditioned byan amplifier and shown on a recorder. (WarningTo avoidoverloading of the
35、load beams, the indicated maximum normalload must not be exceeded.)6.12 For the Schulze Ring Shear Tester RST-01.01 differentshear cells are available. The dimensions of the Standard celland a smaller cell can be taken from Table 2 and Fig. 7. Forspecial purposes (for example, reduced internal volum
36、e) otherdimensions are also available. The following table provides arough indication of the applicability of various cell sizes basedon maximum particle size of the bulk solid (monodisperse =narrow particle size distribution, for example, plastics pellets,grain). Values in parentheses are valid if
37、particles are notbrittle.3The boldface numbers in parentheses refer to the list of references at the end ofthis standard.D6773 162Shear cell typemaximum particle size, xmaxmonodisperse broad distribution, 0 .xmaxM 5 mm 10 mmS 2.5 mm 5 mmMV10 1 (1.5) mm 2 (3) mmSV10 0.75 (1) mm 1.5 (2) mm6.13 The tim
38、e consolidation bench serves for the storage ofshear cells with bulk solid specimens under load.6.13.1 The time consolidation bench (Fig. 9) is composed ofa frame Z1, on which are fastened three supporting plates Z2.One small shear cell (type S, volume approx. 200 cm3) can beplaced on each plate. Th
39、e shape of the plate Z2 centers theshear cell.6.13.2 Through the central depression of the time consoli-dation crossbeam 26 the normal load is exerted during timeconsolidation as shown in the left part of Fig. 9. The lower endof the loading rod Z4 is equipped with a central tip.6.13.3 The transparen
40、t cylindrical plastic cap Z3, whenpressed on plate Z2, protects the specimens from the surround-ing atmosphere (for example, to reduce changes of the mois-ture (water) of the bulk solid specimens). This cap Z3 is joinedto the loading rod Z4 through a rubber bellows Z8.6.13.4 At the upper end of the
41、loading rod Z4 a disk Z5 isfastened for supporting applied mass pieces by which thevertical load for time consolidation is applied.6.13.5 The fixing screw Z6 serves for the fixation of theloading rod Z4 in the upper position (Fig. 9, on the right).6.14 The wall friction shear cells allow the measure
42、ment ofwall yield loci from which wall friction angles can be calcu-lated.6.14.1 The bottom ring 48 of the wall friction shear cell (seeFig. 10) contains the wall material coupon to be tested.6.14.2 To prevent any relative circumferential displacementbetween the bottom ring 48 and the wall material
43、coupon, fourdriving pins 50 are installed at the outer wall of the bottom ring48. The annular wall material coupon has to be provided withnotches for these driving pins so that bottom ring and wallmaterial coupon are interlocked. The required dimensions ofthe wall material coupon are shown in Fig. 1
44、1.6.14.3 The lid 49 (Fig. 12) has bent bars from stainless steelto prevent slipping of the bulk solid at the lid of the shear cell.Additionally, the lid of a wall friction shear cell is providedwith downwards protruding edges at the inner and outer radius.FIG. 1 Ring Shear Tester (overall view)D6773
45、 1636.14.4 The dimensions of the wall friction shear cell areshown in Table 1 and Fig. 13.6.15 A spatula having a rigid, sharp, straight blade at least50 % longer than the width of the annulus of the shear cell, andat least 20 mm wide, is needed.6.16 Alaboratory balance having a maximum capacity of
46、atleast 5 kg with a precision of 0.01 % or better is required.7. Specimen Preparation7.1 The laboratory used for powder testing should be free ofvibrations caused by traffic or heavy machinery. Ideally, theroom should be temperature and humidity controlled, or, if thisis not possible, it should be m
47、aintained at nearly constantambient conditions. Direct sunlight, especially on the timeconsolidation bench, is to be avoided.NOTE 3Temperature- and humidity-sensitive materials may need tobe tested at different temperatures and moisture (water) contents, becausethis often happens in industrial envir
48、onments. The laboratory environmentmust approximate production for meaningful testing.7.2 Setup:7.2.1 Shift the movable counterbalance 29 along the balancearm to adjust the force caused by the counterbalance mass.NOTE 4The fixation screw 18 (knurled screw) fixes the counterbal-ance 29 on the balance
49、 arm.7.2.1.1 After unscrewing the knurled screw, which is themajor part of the movable mass 30, shift the movable mass 30along the balance arm, if necessary, for more precise adjust-ment of the force caused by the counterbalance mass.NOTE 5When the counterbalance mass is well adjusted, the lid,crossbeam, tie rods, and hanger do not press on the bulk solid; that is, thevertical stress at the surface of the bulk solid is equal to zero.7.2.2 Adjust the seatings 16 to level the lid 7.7.2.3 Adjust the four adjustable stands 3 on base 1 (Fig. 5)to level the Ring Shear Tester.
