1、Designation: D 4320 04Standard Practice forLaboratory Preparation of Chemically Grouted SoilSpecimens for Obtaining Design Strength Parameters1This standard is issued under the fixed designation D 4320; the number immediately following the designation indicates the year oforiginal adoption or, in th
2、e case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers the laboratory preparation ofchemically grouted soil specimens
3、for use in laboratory tests todetermine design strength parameters.NOTE 1This practice may not be applicable to grout mixtures with geltimes shorter than the time required to saturate the specimen with grout.1.2 The specimens are intended for both strength andmodulus determination in unconfined and
4、confined compres-sion testing.NOTE 2Preparation methods for specimens to be used for otherpurposes are described in Test Methods D 4219 and D 5202.1.3 This practice requires the injection of grout into soilspecimens already fabricated to a desired density.1.4 All observed and calculated values shall
5、 conform to theguidelines for significant digits and rounding established inPractice D 6026.1.4.1 The method used to specify how data are collected,calculated, or recorded in this standard is not directly related tothe accuracy to which the data can be applied in design or otheruses, or both. How on
6、e applies the results obtained using thisstandard is beyond its scope.1.5 The values stated in inch-pound units are to be regardedas standard, except as noted below. The values given inparentheses are mathematical conversions to SI units, whichare provided for information only and are not considered
7、standard.1.6 This standard 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 requirements prior to use.1.7 T
8、his practice offers a set of instructions for performingone or more specific operations. This document cannot replaceeducation or experience and should be used in conjunction withprofessional judgment. Not all aspects of this practice may beapplicable in all circumstances. This ASTM standard is noti
9、ntended to represent or replace the standard of care by whichthe adequacy of a given professional service must be judged,nor should this document be applied without consideration ofa projects many unique aspects. The word “Standard” in thetitle of this document means only that the document has beena
10、pproved through the ASTM consensus process.1.8 The text of this standard references notes and footnoteswhich provide explanatory material. These notes and footnotes(excluding those in tables and figures) shall not be consideredas requirements of the standard.2. Referenced Documents2.1 ASTM Standards
11、:2D 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 3740 Practice for Minimum Requirements for AgenciesEngaged in the Testing and/or Inspection of Soil and Rockas Used in Engineering Design and ConstructionD 4219 Test Method for Unconfined Compressive StrengthIndex Test of Chemical-Grou
12、ted SoilsD 5202 Test Method for Determining Triaxial CompressionCreep Strength of Chemical Grouted SoilsD 6026 Practice for Using Significant Digits in Geotechni-cal Data3. Terminology3.1 Definitions:3.1.1 For definitions of terms in this standard, refer toTerminology D 653.4. Significance and Use4.
13、1 The purpose of this practice is to prepare specimens ofchemically grouted soils for testing in unconfined or triaxialcompression, when the test data is to be used for designpurposes.NOTE 3The quality of the result produced by this standard isdependent on the competence of the personnel performing
14、it, and thesuitability of the equipment and facilities used. Agencies that meet the1This practice is under the jurisdiction of ASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.15 on Stabilization WithAdmixtures.Current edition approved Nov. 1, 2004. Published N
15、ovember 2004. Originallyapproved in 1984. Last previous edition approved in 2002 as D 4320 02.2For 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
16、 Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.criteria of Practice D 3740 are generally considered capable of competentand objective
17、 testing/sampling/inspection/etc. Users of this standard arecautioned that compliance with Practice D 3740 does not in itself assurereliable results. Reliable results depend on many factors; Practice D 3740provides a means of evaluating some of those factors.5. Apparatus5.1 Specimen MoldsMolds are t
18、o be constructed so thatthey may be longitudinally split to allow the removal ofgrouted specimens without the use of a jacking force. Theymay be sized for the preparation of one or multiple specimens(Multiple specimen molds should be externally marked toindicate desired ends of individual specimens,
19、 as an aid inpreparation). Molds shall produce specimens with a length-to-diameter ratio between two and three, (2.5 is recommended)and shall have a tolerance of 60.01 in. (0.25 mm) on theinternal diameter. Molds will have top and bottom capsdesigned to prevent leakage of grout during pressure injec
20、tion.NOTE 4Satisfactory molds, similar to Fig. 1, may be made from anacrylic tube which has been split longitudinally into three pieces (Fig. 2),which allows for the mold to be assembled and disassembled using siliconrubber seals and hose clamps. Equally satisfactory molds can be made bysplitting tu
21、bes longitudinally with one narrow slit (Fig. 3), which is closedby hose clamps around the tubes and will reopen when the clamps areloosened, thus releasing the specimens. Leakage may be prevented bycovering the slit from the inside with tape. Satisfactory seals of end capsmay be made by threading t
22、he tubing and cap or by external tie rods tohold the caps in place (Fig. 4).5.2 Grout Injection SystemA system composed of thefollowing components (Fig. 5):5.2.1 Mixing Tank, capable of being pressurized to 30.0 psi(207 kPa) without leaking and able to contain all of the groutvolume to be injected i
23、n one grouting operation. The tank willhave an internal mixing device (such as a paddle wheel) or beable to accommodate the use of a magnetic stirrer. The tankwill be fitted with a regulated air-pressure source and pressuregage.NOTE 5Alternatively, proportioning pump sets may be used. Suchequipment
24、may be of advantage when the grout gel times are too short foreffective use of pressure-tank injection equipment.5.2.2 Tubing, capable of transporting the grout from themixing tank to the specimen mold or molds to be injected isrequired. A bleed valve located just before the mold injectioninlet allo
25、ws for air bubbles trapped in the grout lines to beremoved before they move into the specimen.5.3 BalanceA balance or scale of 1000-g capacity, sensi-tive to 0.1 g.5.4 Miscellaneous EquipmentTools such as: spoons,weighing dishes, etc., for handling and weighing soil and anydry grout components, grad
26、uate for measuring water and fluidgrout components, tamping rod or vibrating tool or both forcompaction of specimens to desired density, nylon screenhaving openings small enough to retain the soil to be groutedbut otherwise as large as possible, and scissors for cutting.5.5 Leveling DeviceA leveling
27、 plate attached to a rod ofsufficient length such that the plate can be oriented perpendicu-lar to the long axis of the mold at any height within the mold,capable of fitting inside the mold with approximately 0.25-in.(6.0-mm) clearance.5.6 Moist Room or CabinetA moist room or cabinetcapable of maint
28、aining a temperature of 73.4 6 2.0F (23.0 61.1C) and a relative humidity of not less than 96 % for moistcuring specimens.FIG. 1 Specimen MoldFIG. 2 Three piece multiple specimen moldFIG. 3 Split tube multiple specimen moldD43200425.7 Deviations, from standard curing conditions are to benoted in the
29、report.6. Size of Specimens6.1 Compression test specimens shall be right circularcylinders having a minimum diameter of 1.4 in. (36 mm). Theheight shall be between two and three times the diameter (2.3is recommended).7. Molding Specimens7.1 Either single or multiple specimen molds may be used.7.2 Fo
30、rmation of Soil SpecimenThe mold to be used isassembled (with the top cap removed) and held vertically in astable fashion while the soil sample is prepared using thefollowing procedure:7.2.1 A small piece of screen made of inert material isplaced over the grout inlet at the bottom of the mold to ret
31、ainfilter material.NOTE 6The term “inert” refers to a material which does not interactin any way with the components of the specific grout being used.7.2.2 The lower portion of the mold is filled with a layer(approximately 0.5 to 1 in. (12.5 to 25.4 mm) of coarse sandor pea gravel to serve as a filt
32、er to disperse grout over the entirearea of the specimen.7.2.3 Insert the leveling device and smooth the surface ofthe filter material perpendicular to the long axis of the mold.Remove the leveling device and insert a piece of inert screen,having a diameter no more than 0.1 in. (2.5 mm) smaller than
33、the inside of the mold. Position the screen flat on the filtersurface.7.2.4 The soil to be grouted is placed in layers and com-pacted to the desired density.NOTE 7Compaction may be done by tamping, tapping, or vibration.The method used shall be noted in the report. Satisfactory density controlcan be
34、 obtained by weighing sufficient soil to produce a 1-in. (25-mm)layer at the desired density and compacting this soil until a 1-in. layerthickness is obtained. If a multiple specimen mold is used, an inert screenshall be inserted at the interface between the specimens, as noted on theoutside of the
35、mold. When the top specimen is compacted and the inertscreen is in place, construct the top filter as in 7.2.2 and assemble the topcap.FIG. 4 Schematic Diagram of Specimen Preparation MoldD43200437.2.5 Alternatively, inert porous discs may be placed on topand at the bottom of specimens prior to grou
36、ting, so that thesamples will not require future capping. Discs shall haveporosities equal to or greater than that of the ungroutedspecimen and shall fit the specimen molds with a clearance ofbetween 0.01 to 0.02 in. (0.25 to 0.5 mm). When molds formultiple specimens are used, inert screens shall be
37、 usedbetween adjacent top and bottom discs.8. Grout Injection8.1 Fill the grout injection tank with enough water torepresent three times the volume of voids in the soil specimens,and pump this water through the specimens from the bottom tothe top under a pressure of 5 psi (34.5 kpa) or less to enhan
38、cesaturation. If this process takes less than 30 min, let the sampleremain filled with water until 30 min has elapsed.8.1.1 Tap water may be used whenever its composition issimilar to site ground water, or whenever it does not changegrout characteristics from those obtained with deionized water.Deio
39、nized water may be used, when the use of tap water isquestionable. Site ground water or site supply water may alsobe used.NOTE 8Presaturation is not required for soils expected to be groutedabove the ground water table.8.2 Pour the predetermined quantities of the grout constitu-ents into the empty i
40、njection tank and mix as required, but forless than 20 % of the gel time. Using a mixing propeller or amagnetic stirrer is permissible during the injection period forthose grouts which would be similarly handled in the field.8.3 Apply the design injection air pressure to the injectiontank (10 to 20
41、psi (69 to 138 kPa) depending on grout viscosityand gelling time) and maintain constant during the pumpingprocess. Injection should continue until the effluent shows thatthe water in the specimens has been replaced with grout. Aspecimen of this material shall be taken for a gel time check.8.4 Leave
42、specimens within the molds for at least longenough so that they can be removed without physical damage.For low concentration silicate-based grouts, this period may beas long as 48 h. For acrylamide and acrylate grouts, this periodmay be only a few minutes longer than the gel time.9. Curing Specimens
43、9.1 Leave the specimens in the molds when they are to betested within 16 h. After 16 h, the specimens may be removedfrom the mold provided that they have cured sufficiently to beundamaged by handling. Specimens removed from molds shallbe sealed in plastic or cured in a moist room, as specified insec
44、tion 5.6 from the time of gelation until tested.NOTE 9Other curing environments, such as soaking in water, airdrying, alternate wetting and drying, may be specified depending upon theintended end use of the data. These procedures shall be given in detail inthe report.FIG. 5 Schematic Representation
45、of Injection SystemsD432004410. Report10.1 The report shall include the following:10.1.1 Specimen identification number, classification, mois-ture content and other physical data which may be pertinent,10.1.2 Grout components and proportions, temperature, vis-cosity, gel time, and water source,10.1.
46、3 Gradation of soil and dry and mass density ofspecimens as formed, dimensions and method of compaction,and temperature,10.1.4 Details of curing environment and duration,10.1.5 Deviations from standards, and10.1.6 Dimensions of sample and mass density at time oftest.11. Keywords11.1 chemical grout;
47、chemical grouted soils; curing condi-tions; grouting; grout injection; strength; unconfined compres-sive strengthSUMMARY OF CHANGESIn accordance with Committee D18 policy, this section identifies the location of changes to this standard sincethe last edition (2002) that may impact the use of this st
48、andard.(1) Changed “Test Method” to “Practice” in title and through-out standard.(2) Inserted new sections 1.4 and 1.4.1 regarding guidelinesfor significant digits. Renumbered subsequent sections.(3) Expanded the statement in section 1.5 to reflect guidancein D18 Standards Preparation Manual.(4) Ins
49、erted new section 1.7 on “Professional Judgment” asper Committee D18 policy.(5) Inserted new section 1.8 containing the ASTM policystatement on notes and footnotes and added Practice D 6026 tothe Referenced Documents section.(6) Revised Section 3 on Terminology to reflect CommitteeD18 policy.(7) Changed Note 6 to section 5.7 as this is mandatoryinformation.(8) Removed Section 11 on Precision and Bias as it is notneeded in Practices.(9) Updated “Summary of Changes” section.ASTM International takes no position respecting the validity of any patent rights asserted i
