1、Designation: D5239 04 D5239 12Standard 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 rev
2、ision. A number 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 practice covers procedures for characterizing fly ash to be used in soil stabilization. This practice lists representati
3、vetest methods for determining the chemical, physical, and cementitious properties of fly ash. A broad guideline is provided inAppendix X1 that explains the significance of these properties in soil stabilization.1.2 All observed and calculated values shall conform to the guidelines for significant d
4、igits and rounding established in PracticeD6026.1.2.1 The method used to specify how data are collected, calculated, or recorded in this standard is not directly related to theaccuracy to which the data can be applied in design or other uses, or both. How one applies the results obtained using this
5、standardis beyond its scope.1.3 The values stated in SI units are to be regarded as the standard. The inch-pound equivalents are shown for information only.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user o
6、f this standard to establish appropriate safety and health practices and determine the applicability of regulatoryrequirements prior to use.1.5 This practice offers a set of instructions for performing one or more specific operations. This document cannot replaceeducation or experience and should be
7、 used in conjunction with professional judgment. Not all aspects of this practice may beapplicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which theadequacy of a given professional service must be judged, nor should this document be ap
8、plied without consideration of a projectsmany unique aspects. The word “Standard” in the title of this document means only that the document has been approved throughthe ASTM consensus process1.6 The text of this standard references notes and footnotes which provide explanatory material. These notes
9、 and footnotes(excluding those in tables and figures) shall not be considered as requirements of the standard.2. Referenced Documents2.1 ASTM Standards:2C25 Test Methods for Chemical Analysis of Limestone, Quicklime, and Hydrated LimeC109/C109M Test Method for Compressive Strength of Hydraulic Cemen
10、t Mortars (Using 2-in. or 50-mm Cube Specimens)C191 Test Methods for Time of Setting of Hydraulic Cement by Vicat NeedleC265 Test Method for Water-Extractable Sulfate in Hydrated Hydraulic Cement MortarC305 Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic ConsistencyC
11、311 Test Methods for Sampling and Testing Fly Ash or Natural Pozzolans for Use in Portland-Cement ConcreteC593 Specification for Fly Ash and Other Pozzolans for Use With Lime for Soil StabilizationC821 Specification for Lime for Use with PozzolansD653 Terminology Relating to Soil, Rock, and Containe
12、d FluidsD1293 Test Methods for pH of WaterD3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used inEngineering Design and ConstructionD5370 Specification for Pozzolanic Blended Materials in Construction Applications1 This practice is under
13、the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.15 on Stabilization WithAdmixtures.Current edition approved Nov. 1, 2004July 1, 2012. Published December 2004September 2012. Originally approved in 1992. Last previous edition approved in 199
14、82004as D5239 98.D5239 04. DOI: 10.1520/D5239-04.10.1520/D5239-12.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM
15、website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult p
16、rior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1
17、9428-2959. United States1D6026 Practice for Using Significant Digits in Geotechnical Data3. Terminology3.1 Definitions:3.1.1 For common definitions of terms in this standard, refer to Terminology D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 non self-cementing fly ash, nfly ash produ
18、ced from 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 the combustion of pulverized or crushed coal. This fly ash, in additionto having pozzolanic properties, sets and hardens
19、by chemical interaction with water and is capable of doing so under water.3.2.3 stabilizing admixtures, nadmixtures used to improve soil properties such as increased soil freeze-thaw durability,stiffness, and strength; reduction of permeability, plasticity, and swelling; increased control of soil co
20、mpressibility and moisture.4. Significance and Use4.1 This practice is intended for use with fly ash that can be used separately or along with other stabilizing admixtures toimprove soil properties.4.2 The characterization of the physical and chemical properties of the fly ash shall assist in the ev
21、aluation of the fly ash forsoil stabilization.4.3 This practice is not intended to limit the flexibility of design in soil stabilization. The degree of success attained in soilstabilization is highly dependent on the particular combination of soil, fly ash, and other additives and the construction p
22、rocedureused. Demonstrated sound engineering procedures that result in appropriate physical characteristics are acceptable. The selectionof appropriate materials, applicable tests, acceptance criteria, and specification is the responsibility of the design engineer.NOTE 1The quality of the result pro
23、duced by this standard is dependent on the competence of the personnel performing it, and the suitability of theequipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objectivetesting/sampling/inspection/etc. Users of this s
24、tandard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliableresults depend on many factors; Practice D3740 provides a means of evaluating some of those factors.5. Fly Ash Quality Assurance Program5.1 Pre-QualificationA fly ash is pre-qualified if it
25、is sampled in accordance with Method C311 and a quality history is madeavailable consisting of six months of recent test results. The type of tests performed and their frequency shall be acceptable to thepurchaser.NOTE 2The intent of the quality history is not to accept or reject the fly ash with re
26、gard to specified limits but to provide an evaluation of the flyash and its uniformity.5.2 ProjectDuring the project, spot-checking of a pre-qualified fly ash shall occur at the sampling and testing frequencyestablished by the purchaser. A fly ash that is not pre-qualified shall be sampled at the so
27、urce at a minimum frequency of onesample for each (91 mg) 100 tons made available for sale and be sampled at the job site at a minimum frequency of one samplefor every (23 mg) 25 tons. The type of tests performed and their frequency shall be acceptable to the purchaser.6. Determination of Fly Ash Ch
28、aracteristics6.1 Determine loss on ignition, moisture, and major oxides in accordance with Method C311.6.2 Free LimeDetermine the free lime content in fly ash in accordance with available Lime Index Method of Test Method C25(Hydrated Lime Procedure).6.3 FinenessDetermine the amount retained when wet
29、 sieved on a 45 m (No. 325) sieve in accordance with the proceduredescribed in Method C311.6.4 Self-Cementing PropertiesDetermine the self-cementing properties of fly ash by the compressive strength method givenin Test Method C109/C109M except use no sand nor Portland cement and mixtures shall conta
30、in fly ash plus tap water atwater-to-fly ash weight ratio of 0.35. Test compressive strength at one and seven days. Mix the paste in accordance with MethodC305. Mixing time may have to be modified for quick-setting fly ashes.6.4.1 Very Self-Cementing Fly AshCompressive strengths greater than (345 MP
31、a) 500 psi at seven days.6.4.2 Moderately Self-Cementing Fly Ash Compressive strengths greater than or equal to (70 MPa) 100 psi but less than orequal to (345 MPa) 500 psi at seven days.6.4.3 Non Self-Cementing Fly AshCompressive strengths less than (70 MPa) 100 psi at seven days.6.5 Lime-Pozzolanic
32、 ActivityDetermine the lime-pozzolan strength development in accordance with Specification C593. Forpurposes of standardization, the lime must meet Specification C821.6.6 Strength Activity Index with Portland Cement Determine the strength activity index with Portland Cement in accordancewith Method
33、C311.D5239 1226.7 Setting TimeDetermine the set of fly ash-water pastes at water-to-fly ash weight ratio of 0.35 by vicat needle in accordancewith Test Method C191.6.8 pHDetermine the pH of the fly ash by adding 20 g fly ash to 80 mL distilled water. Stir the mixture to disperse the flyash. Leave th
34、e covered beaker undisturbed for 2 h and then determine pH in accordance with Test Method D1293.6.9 SulfatesDetermine water-soluble sulfates in accordance with Test Method C265 except stir 1 g fly ash into 100 mLdistilled water for 2 min and filter and wash the residue thoroughly with 3 to 10 mL ali
35、quots of room temperature water using arapid-filtering, acid-washed filter paper folded inside a fine-textured acid-washed filter paper.6.9.1 Determine total sulfate in accordance with Method C311.7. Report7.1 The report of the physical and chemical analysis of the fly ash shall include the sampling
36、 date and location, the identity oftests performed, and shall provide a summary of the essential data as outlined in Section 6.8. Keywords8.1 fly ash; pozzolan, self-cementing fly ash; soil; soil stabilizationAPPENDIX(Nonmandatory Information)X1. SOIL STABILIZATION WITH FLY ASHX1.1 Non Self-Cementin
37、g Fly Ash Stabilization:X1.1.1 Non self-cementing fly ash, by itself, has little effect on soil stabilization. It is a poor source of calcium and magnesiumions. The particle size of fly ash may exceed that of the voids in fine-grained soils, precluding its use as a filler. However, this flyash in po
38、orly graded sandy soils may be a suitable filler and, as such, may aid in compaction, may increase density, and maydecrease permeability.X1.1.2 Non Self-Cementing Fly Ash Mixed With Cement or LimeThe advantage of adding fly ash to fine-grained soils, alongwith cement or lime, is for its pozzolanic p
39、roperties and improved soil texture. Some clays are pozzolanic in nature and onlyrequire lime to initiate the pozzolanic reaction. The use of this fly ash is suitable with clays requiring lime modification, providedlime is added to promote the pozzolanic reaction. If lime is required, it should be a
40、dded to the soil up to 24 h prior to fly ashaddition.addition depending upon the plasticity soil (e.g. soils classified as SC or CL by the Unified Soil Classification System).Pre-blended lime and fly ash as approved by the engineer may be spread in a single application on SC or CL classified soils.X
41、1.2 Self-Cementing Fly Ash Stabilization:X1.2.1 This fly ash is a better source of calcium and magnesium ions although not as good as lime or Portland cement.Self-cementing fly ash contains varying amounts of free (uncombined) lime (0 to 7 % CaO by weight) that can provide cationexchange and ion cro
42、wding to fine-grained soils when used in significant amounts. It has been used successfully to control swellpotential of expansive soils. It has also been used to stabilize coarse-grained soils.NOTE X1.1Though some fly ashes have up to 35 % CaO (elemental chemical analysis), most of the calcium is c
43、ombined as calcium aluminates, calciumsilicates, and calcium sulfate.X1.2.2 The retardation of some very self-cementing fly ashes, using retardation agents, such as: sodium borate, sodium citrate,citric acid, or commercial retarding admixtures, may be necessary to delay the hydration reactions suffi
44、ciently to obtain adequatemixing and compaction in the field. Since the effect of retarders is variable, checks of strength and time of set should be performedon trial batches for each fly ash.D5239 123SUMMARY OF CHANGESIn accordance with Committee D18 policy, this section identifies has identified
45、the location of selected changesto this standardpractice since the last editionissue, D5239(1998)04, that may impact the use of thisstandard.practice. (Approved July 1, 2012)(1) Inserted new sections 1.2) Added Specification D5370 and 1.2.1 regarding guidelines for significant digits. Renumberedsubs
46、equent sections. to Referenced Documents.(2) Inserted section 1.6) Updated X1.1.2 containing the ASTM policy statement on notes and footnotes.to recognize that lowerplasticity soils require reduced contact time with the lime prior to the addition of fly ash, and to recognize technologies that blendt
47、he two products together for use in lower plasticity soils.(3) Revised section 2.1 to reflect correct titles of standards. Removed references that are not present in document. Insertedreferences to Practices D3740 and D6026.(4) Revised Section 3 to reflect style and form of D18 Standards Preparation
48、 Manual.(5) Inserted Note 1 as per D18 Standards Preparation Manual. Renumbered 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 sta
49、ndard are expressly advised that determination of the validity of any 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 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 meetin
