1、Designation: D5239 121Standard Practice forCharacterizing Fly Ash for Use in Soil Stabilization1This standard is issued under the fixed designation D5239; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEEditorially updated units of measurement statement in April 2018.1. Scope*1.1 This practice covers procedures for characterizing flyash to be
3、 used in soil stabilization. This practice lists represen-tative test 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 calc
4、ulated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.2.1 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 otheruse
5、s, or both. How one applies the results obtained using thisstandard is beyond its scope.1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses after SI units areprovided for information only and are not considered standard.1.4 This standard does not purport
6、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, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This practice offers a set of
7、instructions for performingone or more specific operations. This document cannot replaceeducation or experience and should be used in conjunctionwith professional judgment. Not all aspects of this practice maybe applicable in all circumstances. This ASTM standard is notintended to represent or repla
8、ce 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 beenapproved through the ASTM cons
9、ensus process1.6 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.1.7 This international standard was developed in accor-dance with inter
10、nationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C25 T
11、est Methods for Chemical Analysis of Limestone,Quicklime, and Hydrated LimeC109/C109M Test Method for Compressive Strength ofHydraulic Cement Mortars (Using 2-in. or 50-mm CubeSpecimens)C191 Test Methods for Time of Setting of Hydraulic Cementby Vicat NeedleC265 Test Method for Water-Extractable Sul
12、fate in HydratedHydraulic Cement Mortar (Withdrawn 2017)3C305 Practice for Mechanical Mixing of Hydraulic CementPastes and Mortars of Plastic ConsistencyC311 Test Methods for Sampling and Testing Fly Ash orNatural Pozzolans for Use in Portland-Cement ConcreteC593 Specification for Fly Ash and Other
13、Pozzolans for UseWith Lime for Soil StabilizationC821 Specification for Lime for Use with PozzolansD653 Terminology Relating to Soil, Rock, and ContainedFluidsD1293 Test Methods for pH of WaterD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock a
14、sUsed in Engineering Design and Construction1This 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 July 1, 2012. Published September 2012. Originallyapproved in 19
15、92. Last previous edition approved in 2004 as D5239 04. DOI:10.1520/D5239-12E01.2For 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
16、onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*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 StatesThis international
17、standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1D
18、5370 Specification for Pozzolanic Blended Materials inConstruction ApplicationsD6026 Practice for Using Significant Digits in GeotechnicalData3. Terminology3.1 Definitions:3.1.1 For common definitions of terms in this standard, referto Terminology D653.3.2 Definitions of Terms Specific to This Stand
19、ard:3.2.1 non self-cementing fly ash, nfly ash produced fromthe 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
20、to having pozzolanic properties, sets and hardens bychemical interaction with water and is capable of doing sounder water.3.2.3 stabilizing admixtures, nadmixtures used to improvesoil properties such as increased soil freeze-thaw durability,stiffness, and strength; reduction of permeability, plastic
21、ity, andswelling; increased control of soil compressibility and mois-ture.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 pr
22、op-erties of the fly ash shall assist in the evaluation 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
23、ash, and other additives and the constructionprocedure used. 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 thedesig
24、n engineer.NOTE 1The quality of the result produced by this standard isdependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria of Practice D3740 are generally considered capable of competentand objective test
25、ing/sampling/inspection/etc. Users of this standard arecautioned that compliance with Practice D3740 does not in itself assurereliable results. Reliable results depend on many factors; Practice D3740provides a means of evaluating some of those factors.5. Fly Ash Quality Assurance Program5.1 Pre-Qual
26、ificationA fly ash is pre-qualified if it issampled in accordance with Method C311 and a quality historyis made available consisting of six months of recent test results.The type of tests performed and their frequency shall beacceptable to the purchaser.NOTE 2The intent of the quality history is not
27、 to accept or reject thefly ash with regard to specified 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 notpr
28、e-qualified shall be sampled at the source at a minimumfrequency 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 purch
29、aser.6. Determination of Fly Ash Characteristics6.1 Determine 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 FinenessDeter
30、mine the amount retained when wetsieved on a 45 m (No. 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 C109/C109M except use no sandnor Portland
31、cement and mixtures shall contain fly ash plus tapwater at water-to-fly ash weight ratio of 0.35. Test compressivestrength at one and seven days. Mix the paste in accordancewith Method C305. Mixing time may have to be modified forquick-setting fly ashes.6.4.1 Very Self-Cementing Fly AshCompressive s
32、trengthsgreater than (345 MPa) 500 psi at seven days.6.4.2 Moderately Self-Cementing Fly Ash Compressivestrengths 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 seve
33、n days.6.5 Lime-Pozzolanic ActivityDetermine the lime-pozzolanstrength development in accordance with Specification C593.For purposes of standardization, the lime must meet Specifi-cation C821.6.6 Strength Activity Index with Portland CementDetermine the strength activity index with Portland Cementi
34、n accordance with Method C311.6.7 Setting TimeDetermine the set of fly ash-water pastesat water-to-fly ash weight ratio of 0.35 by vicat needle inaccordance with Test Method C191.6.8 pHDetermine the pH of the fly ash by adding 20 g flyash to 80 mL distilled water. Stir the mixture to disperse the fl
35、yash. Leave the covered beaker undisturbed for 2 h and thendetermine pH in accordance with Test Method D1293.6.9 SulfatesDetermine water-soluble sulfates in accor-dance with Test Method C265 except stir1gflyashinto 100mL distilled water for 2 min and filter and wash the residuethoroughly with 3 to 1
36、0 mL aliquots of room temperature waterusing a rapid-filtering, acid-washed filter paper folded inside afine-textured acid-washed filter paper.6.9.1 Determine total sulfate in accordance with MethodC311.D5239 12127. Report7.1 The report of the physical and chemical analysis of thefly ash shall inclu
37、de the sampling date and location, the identityof tests 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; soilstabilizationAPPENDIX(Nonmandatory Information)X1. SOIL STABILIZATION WITH FLY ASHX1.1 Non
38、Self-Cementing Fly Ash Stabilization:X1.1.1 Non 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 fl
39、y ash in poorly graded sandy soils may be asuitable 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 poz
40、zolanic properties andimproved soil texture. Some 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 shoul
41、d be added to the soil up to 24 h priorto fly ash addition depending upon the plasticity soil (e.g. soilsclassified as SC or CL by the Unified Soil ClassificationSystem). Pre-blended lime and fly ash as approved by theengineer may be spread in a single application on SC or CLclassified soils.X1.2 Se
42、lf-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 crowding to
43、 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 combined as
44、calciumaluminates, 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 sufficiently to ob
45、tainadequate 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 CHANGESCommittee D18 has identified the location of selected changes to this practice since the last issue, D5
46、23904,that may impact the use of this practice. (Approved July 1, 2012)(1) Added Specification D5370 to Referenced Documents.(2) Updated X1.1.2 to recognize that lower plasticity soilsrequire reduced contact time with the lime prior to the additionof fly ash, and to recognize technologies that blend
47、 the twoproducts together for use in lower plasticity soils.D5239 1213ASTM 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 a
48、ny such 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
49、invited 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 fair 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. Individu
