1、Designation: D 5239 04Standard Practice forCharacterizing Fly Ash for Use in Soil Stabilization1This standard is issued under the fixed designation D 5239; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、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 procedures for characterizing flyash to be used in soil stabilization. This practice lists represen-tative tes
3、t methods for determining the chemical, physical, andcementitious properties of fly ash. A broad guideline is pro-vided in Appendix X1 that explains the significance of theseproperties in soil stabilization.1.2 All observed and calculated values shall conform to theguidelines for significant digits
4、and rounding established inPractice D 6026.1.2.1 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 one applies the results obtained using thisstandard
5、 is beyond its scope.1.3 The values stated in SI units are to be regarded as thestandard. The inch-pound equivalents are shown for informa-tion only.1.4 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 s
6、tandard to establish appro-priate safety and health practices and determine the applica-bility of regulatory requirements prior to use.1.5 This practice offers a set of instructions for performingone or more specific operations. This document cannot replaceeducation or experience and should be used
7、in conjunctionwith professional judgment. Not all aspects of this practice maybe applicable in all circumstances. This ASTM standard is notintended 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 wit
8、hout consideration ofa projects many unique aspects. The word “Standard” in thetitle of this document means only that the document has beenapproved through the ASTM consensus process1.6 The text of this standard references notes and footnoteswhich provide explanatory material. These notes and footno
9、tes(excluding those in tables and figures) shall not be consideredas requirements of the standard.2. Referenced Documents2.1 ASTM Standards:2C 25 Test Methods for Chemical Analysis of Limestone,Quicklime, and Hydrated LimeC 109/C 109M Test Method for Compressive Strength ofHydraulic Cement Mortars (
10、Using 2-in. or 50-mm CubeSpecimens)C 191 Test Method for Time of Setting of Hydraulic Ce-ment by Vicat NeedleC 265 Test Method for Water-Extractable Sulfate in Hy-drated Hydraulic Cement MortarC 305 Practice for Mechanical Mixing of Hydraulic CementPastes and Mortars of Plastic ConsistencyC 311 Test
11、 Methods for Sampling and Testing Fly Ash orNatural Pozzolans for Use as a Mineral Admixture inPortland-Cement ConcreteC 593 Specification for Fly Ash and Other Pozzolans forUse with LimeC 821 Specification for Lime for Use with PozzolansD 653 Terminology Relating to Soil, Rock and ContainedFluidsD
12、1293 Test Methods for pH of WaterD 3740 Practice for Minimum Requirements for AgenciesEngaged in the Testing and/or Inspection of Soil and Rockas Used in Engineering Design and ConstructionD 6026 Practice for Using Significant Digits in Geotechni-cal Data3. Terminology3.1 Definitions:3.1.1 For commo
13、n definitions of terms in this standard, referto Terminology D 653.3.2 Definitions of Terms Specific to This Standard:1This practice is under the jurisdiction of ASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.15 on StabilizationAdmixtures.Current edition appr
14、oved Nov. 1, 2004. Published December 2004. Originallyapproved in 1992. Last previous edition approved in 1998 as D 5239 98.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, r
15、efer to the standards Document 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.3.2.1 non self-cementing fly ash, nfly ash produced from
16、the combustion of pulverized or crushed coal. This fly ash haspozzolanic properties and no self-cementing properties.3.2.2 self-cementing fly ash, nfly ash produced from thecombustion of pulverized or crushed coal. This fly ash, inaddition to having pozzolanic properties, sets and hardens bychemical
17、 interaction with water and is capable of doing sounder water.3.2.3 stabilizing admixtures, nadmixtures used to im-prove soil properties such as increased soil freeze-thaw dura-bility, stiffness, and strength; reduction of permeability, plas-ticity, and swelling; increased control of soil compressib
18、ilityand moisture.4. Significance and Use4.1 This practice is intended for use with fly ash that can beused separately or along with other stabilizing admixtures toimprove soil properties.4.2 The characterization of the physical and chemical prop-erties of the fly ash shall assist in the evaluation
19、of the fly ashfor soil stabilization.4.3 This practice is not intended to limit the flexibility ofdesign in soil stabilization. The degree of success attained insoil stabilization is highly dependent on the particular combi-nation of soil, fly ash, and other additives and the constructionprocedure u
20、sed. Demonstrated sound engineering proceduresthat result in appropriate physical characteristics are accept-able. The selection of appropriate materials, applicable tests,acceptance criteria, and specification is the responsibility of thedesign engineer.NOTE 1The quality of the result produced by t
21、his standard isdependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria of Practice D 3740 are generally considered capable of competentand objective testing/sampling/inspection/etc. Users of this standard are
22、cautioned 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. Fly Ash Quality Assurance Program5.1 Pre-QualificationA fly ash is pre-qualified if it issampled i
23、n accordance with Method C311 and a qualityhistory is made available consisting of six months of recent testresults. The type of tests performed and their frequency shall beacceptable to the purchaser.NOTE 2The intent of the quality history is not to accept or reject thefly ash with regard to specif
24、ied limits but to provide an evaluation of thefly ash and its uniformity.5.2 ProjectDuring the project, spot-checking of a pre-qualified fly ash shall occur at the sampling and testingfrequency established by the purchaser. A fly ash that is notpre-qualified shall be sampled at the source at a minim
25、umfrequency of one sample for each (91 mg) 100 tons madeavailable for sale and be sampled at the job site at a minimumfrequency of one sample for every (23 mg) 25 tons. The typeof tests performed and their frequency shall be acceptable tothe purchaser.6. Determination of Fly Ash Characteristics6.1 D
26、etermine loss on ignition, moisture, and major oxidesin accordance with Method C311.6.2 Free LimeDetermine the free lime content in fly ash inaccordance with available Lime Index Method of Test MethodC25(Hydrated Lime Procedure).6.3 FinenessDetermine the amount retained when wetsieved on a 45 m (No.
27、 325) sieve in accordance with theprocedure described in Method C311.6.4 Self-Cementing PropertiesDetermine the self-cementing properties of fly ash by the compressive strengthmethod given in Test Method C 109/C 109M except use nosand nor Portland cement and mixtures shall contain fly ashplus tap wa
28、ter at water-to-fly ash weight ratio of 0.35. Testcompressive strength at one and seven days. Mix the paste inaccordance with Method C 305. Mixing time may have to bemodified for quick-setting fly ashes.6.4.1 Very Self-Cementing Fly AshCompressive strengthsgreater than (345 MPa) 500 psi at seven day
29、s.6.4.2 Moderately Self-Cementing Fly AshCompressivestrengths greater than or equal to (70 MPa) 100 psi but lessthan or equal to (345 MPa) 500 psi at seven days.6.4.3 Non Self-Cementing Fly AshCompressive strengthsless than (70 MPa) 100 psi at seven days.6.5 Lime-Pozzolanic ActivityDetermine the lim
30、e-pozzolan strength development in accordance with Specifica-tion C 593. For purposes of standardization, the lime mustmeet Specification C 821.6.6 Strength Activity Index with Portland CementDetermine the strength activity index with Portland Cement inaccordance with Method C311.6.7 Setting TimeDet
31、ermine the set of fly ash-water pastesat water-to-fly ash weight ratio of 0.35 by vicat needle inaccordance with Test Method C 191.6.8 pHDetermine the pH of the fly ash by adding 20 g flyash to 80 mL distilled water. Stir the mixture to disperse the flyash. Leave the covered beaker undisturbed for 2
32、 h and thendetermine pH in accordance with Test Method D 1293.6.9 SulfatesDetermine water-soluble sulfates in accor-dance with Test Method C 265 except stir1gflyashinto 100mL distilled water for 2 min and filter and wash the residuethoroughly with 3 to 10 mL aliquots of room temperature waterusing a
33、 rapid-filtering, acid-washed filter paper folded inside afine-textured acid-washed filter paper.6.9.1 Determine total sulfate in accordance with MethodC311.7. Report7.1 The report of the physical and chemical analysis of thefly ash shall include the sampling date and location, the identityof tests
34、performed, and shall provide a summary of theessential data as outlined in Section 6.8. Keywords8.1 fly ash; pozzolan, self-cementing fly ash; soil; soilstabilizationD5239042APPENDIX(Nonmandatory Information)X1. SOIL STABILIZATION WITH FLY ASHX1.1 Non Self-Cementing Fly Ash Stabilization:X1.1.1 Non
35、self-cementing fly ash, by itself, has little effecton soil stabilization. It is a poor source of calcium andmagnesium ions. The particle size of fly ash may exceed that ofthe voids in fine-grained soils, precluding its use as a filler.However, this fly ash in poorly graded sandy soils may be asuita
36、ble filler and, as such, may aid in compaction, mayincrease density, and may decrease permeability.X1.1.2 Non Self-Cementing Fly Ash Mixed With Cement orLimeThe advantage of adding fly ash to fine-grained soils,along with cement or lime, is for its pozzolanic properties andimproved soil texture. Som
37、e clays are pozzolanic in nature andonly require lime to initiate the pozzolanic reaction. The use ofthis fly ash is suitable with clays requiring lime modification,provided lime is added to promote the pozzolanic reaction. Iflime is required, it should be added to the soil 24 h prior to flyash addi
38、tion.X1.2 Self-Cementing Fly Ash Stabilization:X1.2.1 This fly ash is a better source of calcium andmagnesium ions although not as good as lime or Portlandcement. Self-cementing fly ash contains varying amounts offree (uncombined) lime (0 to 7 % CaO by weight) that canprovide cation exchange and ion
39、 crowding to fine-grained soilswhen used in significant amounts. It has been used successfullyto control swell potential of expansive soils. It has also beenused to stabilize coarse-grained soils.NOTE X1.1Though some fly ashes have up to 35 % CaO (elementalchemical analysis), most of the calcium is
40、combined as calcium alumi-nates, calcium silicates, and calcium sulfate.X1.2.2 The retardation of some very self-cementing flyashes, using retardation agents, such as: sodium borate, sodiumcitrate, citric acid, or commercial retarding admixtures, may benecessary to delay the hydration reactions suff
41、iciently to obtainadequate mixing and compaction in the field. Since the effectof retarders is variable, checks of strength and time of setshould be performed on trial batches for each fly ash.SUMMARY OF CHANGESIn accordance with Committee D18 policy, this section identifies the location of changes
42、to this standard sincethe last edition (1998) that may impact the use of this standard.(1) Inserted new sections 1.2 and 1.2.1 regarding guidelinesfor significant digits. Renumbered subsequent sections.(2) Inserted section 1.6 containing the ASTM policy statementon notes and footnotes.(3) Revised se
43、ction 2.1 to reflect correct titles of standards.Removed references that are not present in document. Insertedreferences to Practices D 3740 and D 6026.(4) Revised Section 3 to reflect style and form of D18Standards Preparation Manual.(5) Inserted Note 1 as per D18 Standards Preparation Manual.Renum
44、bered subsequent note.(6) Updated “Summary of Changes” section.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such
45、 patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited
46、 either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a f
47、air hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D5239043
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