1、Designation: C1356 07 (Reapproved 2012)Standard Test Method forQuantitative Determination of Phases in Portland CementClinker by Microscopical Point-Count Procedure1This standard is issued under the fixed designation C1356; the number immediately following the designation indicates the year oforigin
2、al adoption or, in the case of revision, the year of last revision. 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 test method covers a systematic procedure formeasuring the
3、percentage volume of the phases in portlandcement clinker by microscopy.1.2 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 t
4、he applica-bility of regulatory limitations prior to use.1.3 The values stated in SI units are to be regarded as thestandard.2. Referenced Documents2.1 ASTM Standards:2C150 Specification for Portland CementC219 Terminology Relating to Hydraulic CementC670 Practice for Preparing Precision and Bias St
5、atementsfor Test Methods for Construction MaterialsD75 Practice for Sampling AggregatesD3665 Practice for Random Sampling of Construction Ma-terials3. Terminology3.1 Definitions:3.1.1 clinker phase, na physically and chemically distinctoptically identifiable portion of the clinker sample, includingb
6、oth principal phases (alite, belite, aluminate, and ferrite),minor phases (for example, free lime, periclase, and alkalisulfates), and voids.3.1.1.1 DiscussionVoids, though not a phase in the senseof being a crystalline compound, are a distinct, identifiableportion of a clinker microstructure.3.1.2
7、voids, nisolated or interconnected open areas in theclinker, also called pores.3.2 Principal Clinker Phases:33.2.1 alite, ncrystalline tricalcium silicate (C3S), modifiedin composition and crystal structure by incorporation of foreignions; the crystals are pseudo-hexagonal with well-definedfaces, th
8、ough less regular shapes commonly occur.3.2.2 aluminate, ntricalcium aluminate (C3A) modified incomposition and crystal structure by incorporation of a sub-stantial proportion of foreign ions; aluminate forms cubiccrystals when relatively pure, and forms identifiable elongatedcrystals commonly calle
9、d “alkali aluminate” when in solidsolution with significant amounts of potassium or sodium, orboth.3.2.3 belite, ncrystalline dicalcium silicate (C2S), modi-fied in composition and crystal structure by incorporation offoreign ions; belite usually occurs as rounded crystals markedby striations formed
10、 by cross sections of lamellae, and mayoccur as single crystals or in clusters.3.2.4 ferrite, na solid solution of approximate composi-tion tetracalcium aluminoferrite (C4AF) modified in composi-tion by variation in the Al/Fe ratio and by substantial incorpo-ration of foreign ions; ferrite is charac
11、terized by highreflectivity in polished sections and is normally the onlystrongly colored compound among the principal clinkerphases.3.2.4.1 DiscussionAluminate and ferrite form most of theinterstitial material between the silicate crystals and, undercertain conditions of cooling, may not be easily
12、identifiable orresolved by ordinary light microscopy.3.3 Minor Clinker Phases:3.3.1 alkali sulfates, nsodium sulfate, potassium sulfate,and double sulfates such as calcium langbeinite(K2SO42CaSO4).3.3.2 free lime, ncalcium oxide (C) found mostly as roundcrystals.1This test method is under the jurisd
13、iction ofASTM Committee C01 on Cementand is the direct responsibility of Subcommittee C01.23 on CompositionalAnalysis.Current edition approved Oct. 1, 2012. Published November 2012. Originallyapproved in 1996. Last previous edition approved in 2007 as C1356 07. DOI:10.1520/C1356-07R12.2For reference
14、d 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.3C = CaO, S = SiO2,A=Al2O3,F=Fe2O3,S=SO3, M = MgO, N = Na2O, andK=K2O in ce
15、ment chemistry notation.*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 States13.3.3 periclase, ncrystalline form of free magnesium ox-ide (M), that has not been taken up in so
16、lid solution with otherphases.3.4 For definitions of other terms relating to hydrauliccements, refer to Terminology C219.4. Summary of Test Method4.1 The test method consists of the preparation and micro-scopical examination of a specimen produced by encapsulatingclinker in a mounting medium and sec
17、tioning the specimen soas to expose the interior of particles for visual examination.Polishing the section surface and treating it with etchants tohighlight specific phases complete the preparation. Duringmicroscopical examination phases are identified and theirproportions determined by a point-coun
18、t procedure. In thisprocedure, the specimen is moved in uniform increments on amicroscope stage, and phases falling under the cross hairs ofthe eyepiece are identified and counted (1-5).5. Significance and Use5.1 This test method provides a relatively simple andreliable microscopical means of measur
19、ing the phase abun-dance of portland cement clinker (Note 1). Microscopical pointcounting provides a direct measure of the clinker phasecomposition in contrast to the calculated Bogue phase compo-sition (Note 2).NOTE 1This test method utilizes a reflected light microscope. Relatedmethods such as tra
20、nsmitted light microscopy, scanning electronmicroscopy, and automated imaging techniques may also be used forclinker analysis but are not presently included in this test method.NOTE 2This test method allows direct determination of the proportionof each individual phase in portland-cement clinker. Th
21、is test method isintended to provide an alternative to the indirect estimation of phaseproportion using the equations in Specification C150 (footnote C in Tablenumber 1 and footnote B in Table number 2).5.2 This test method assumes the operator is qualified tooperate a reflected light microscope and
22、 the requiredaccessories, is able to correctly prepare polished sections anduse necessary etchants, and is able to correctly identify theconstituent phases.5.3 This test method may be used as part of a quality controlprogram in cement manufacturing as well as a troubleshootingtool. Microscopic chara
23、cterization of clinker phases may alsoaid in correlating cement properties and cement performance inconcrete, to the extent that properties and performance are afunction of phase composition.6. Apparatus6.1 Reflected light microscope.6.2 Mechanical stage with stepping increments rangingfrom 0.05 to
24、2.0 mm (to enable analysis of clinkers of differentaverage crystal sizes) and vernier scales graduated in both Xand Y directions.6.3 Microscope objectives of magnification 5, 10, 20,and 40 or other magnifications suitable for the task.NOTE 3The use of reflected light with oil immersion is optional.
25、It ishighly recommended for study of finely crystalline aluminate and ferritewhich typically form the ground mass in which the silicates occur.Reflected light objective lenses with magnification up to 100 designedfor use in oil-immersion are required.6.4 Assorted eyepieces (5, 10, 20) which when com
26、-bined with the objectives described in 6.3 will provide magni-fications up to 800.6.5 Eyepiece reticles (graticulae) with a linear grid patterncontaining 9, 16, or 25 intersections.6.6 Eyepiece micrometer for measuring dimensions of theobject under investigation and calibrated for each magnifica-ti
27、on.6.7 Stage micrometer for the calibration of the eyepiecemicrometer.6.8 Light source that provides uniform and consistent illu-mination of the field and light of constant intensity.6.9 Counting (tallying) device capable of recording up toten categories of data.6.10 Crushing device capable of reduc
28、ing sample particlesize to between 1 and 4 mm.6.11 Riffle sample splitter to reduce sample from initialvolume to approximately 100 g.6.12 Wire cloth sieves with openings suitable for sieving theentire clinker sample to broadly define the model size class,and sieves with 1-mm and 4-mm square openings
29、 to concen-trate particles of recommended size for specimen preparation.6.13 Vacuum impregnation device to force epoxy intoclinker voids. (Vacuum bell jar or desiccator connected to avacuum pump.)6.14 Curing oven, hot plate, slide warmer, or ultravioletlight may be used to accelerate the epoxy harde
30、ning.6.15 Thin, diamond-rimmed wafering saw for sectioningthe encapsulated clinker.6.16 Glass grinding (lapping) plates (300 mm 300 mm 5mm) required only if the mechanical system is not equipped tohandle the final grinding with alumina powder.6.17 Ultrasonic cleaning device (optional) to clean thesa
31、mple prior to, between, and after polishing steps.7. Reagents and Materials7.1 Consumable grinding (lapping) and polishing supplies.After the encapsulated specimen has been cut with the saw, allor most of the following grinding and polishing steps arerequired: 120-, 320-, and 600-grit silicon carbid
32、e grindingpapers or equivalent and 5 m, 0.3 m, and 0.05 m aluminapolishing powders or their equivalent. Diamond grinding discs,silicon carbide paper, or polishing cloths and alumina polishingpowder may be used. Various types of polishing cloths may beused to produce a nearly flat clinker surface or
33、a relief surfaceto aid in identification of periclase (1).47.2 Sample cups (with volumes ranging from 10 to 20 mL)to contain epoxy-clinker mix during hardening.4The boldface numbers in parentheses refer to the list of references at the end ofthis standard.C1356 07 (2012)27.3 Epoxy resin and hardener
34、 for encapsulation of theclinker. Low viscosity resin will facilitate penetration intoclinker voids. When hardened it should have an abrasiveresistance close to that of the clinker to minimize relief duringpolishing. It should be resistant to substances used for washingand etching.7.4 Isopropyl alco
35、hol (2-propanol) for washing the speci-men and for use in the ultrasonic cleaner. Propylene glycol issuitable as a lubricant for the saw blade.7.5 Immersion oil with an index of refraction of 1.51 ifreflected light immersion-oil technique is used.7.6 Etching material to highlight different phases fo
36、r count-ing. (See Appendix X3.)8. Sampling8.1 Take samples of portland-cement clinker in accordancewith the applicable provisions of Practices D75 and D3665 soas to be representative of the quantity of material with whichtesting is concerned (see Appendix X1).8.2 Sieve the initial sample to obtain c
37、linker particlesrepresenting approximately 70 % of the clinker particle sizedistribution, centered about the mode. This particle size inter-val represents a size range of approximately two standarddeviations, one on each side of the mode, and is herein definedas the “bulk mode” (Mb), the combined ma
38、terial between theextremes of the particle size distribution. State the sieve sizesused. If either extreme of the particle size distribution is to bestudied, the selected portion shall be identified as non-modal,and the percentages retained or passing standard sieves shall bestated. The recommended
39、size fraction for microscopicalanalysis is 2 to 4 mm. Therefore, that portion of the initialclinker sample representing the bulk mode shall be crushed,sieved, and riffled to provide approximately 100 g. Wholeclinkers may be encapsulated to study the phase distributionwithin clinker nodules.9. Prepar
40、ation of Sample Specimen9.1 Polished sections shall be polished to a fineness suchthat grinding pits and scratches have been eliminated (seeAppendix X1).9.2 Etching of the clinker surface may be used to facilitateidentification of clinker phases (1); additional information maybe found in the Appendi
41、x X1.10. Counting Procedure10.1 Choose the microscope magnification such that adja-cent reticle grid points do not fall on the same crystal, exceptfor a few unusually large crystals. Magnification from 200 to500 will accommodate most clinkers. Reticles with multiplegrid points are recommended. Singl
42、e crosshair reticles are notsuitable.10.2 Choose the stepping interval such that an entirelydifferent field of view is observed after each step.10.3 Attach a mechanical stage to the microscope. Themechanical stage may be an electrically driven specimencarriage connected to an automatic electronic co
43、unter or asimple hand-operated carriage and counter. Place a smallamount of soft modeling clay on a standard, petrographic glassslide (27 mm 46 mm) and level the sample thereon. Eitheruse a commercial leveling device or use a small spirit level toadjust the mount while pressing it firmly into the cl
44、ay. A tissuepaper between the polished section and the leveling device orspirit level prevents surface scratches. Place the glass slidewith attached clay and leveled mount on the mechanical stage.Check the accuracy of leveling by observing the focus atseveral points on the polished surface. Move to
45、a starting point(the initial field of view from which data will be taken) at theedge of the mount and record the position in the X-Ycoordinate system, using the graduated scales on the mechani-cal stage.10.4 Use a tally sheet or a counting device to record thephases as required. The observer should
46、not keep a mental tallyof any data because of possible bias. Identify and record eachphase under the grid intersections. In some cases, the aluminateand ferrite quantities may be combined and labeled “matrix”.Move the mechanical stage a distance of one stepping intervalin the chosen X or Y direction
47、 to bring another field into view.The phases under the grid points are identified, counted, andthe mechanical stage advanced one stepping interval to anadjacent field of view.This procedure is continued until a rangeof 3000-4000 points are recorded.At the clinker periphery, some of the reticle point
48、s may fallon the encapsulating epoxy that surrounds the clinker particle.Count only points within the clinker, and disregard the reticlepoints over epoxy at the clinker periphery. Thus, the clinkervoid space (porosity), if determined in the point count, does notinclude cavities on the surface of the
49、 clinker particle. As onesteps over irrelevant areas (such as epoxy exterior to the clinkeror severally damaged portions of the polished surface thatobscure the phase identification) the count is temporarilysuspended until a suitable clinker surface again falls under thereticle grid points. Artifacts (for example, blot marks, residualliquids) on the section surface are not to be counted. If theidentity of the phase is obscured by the area formed by the gridintersection, one should consistently use a specified corner ofthe intersection where the ph
