ASTM_C_1356_-_07_2012.pdf

Designation:C135607(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 oforiginal 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 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 the 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 Statementsfor 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,includingboth 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 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,though 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 called“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 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 characterized 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 identifiable orresolved by ordinary light microscopy.3.3 Minor Clinker Phases:3.3.1 alkali sulfates,nsodium sulfate,potassium sulfate,anddoublesulfatessuchascalciumlangbeinite(K2SO42CaSO4).3.3.2 free lime,ncalcium oxide(C)found mostly as roundcrystals.1This test method is under the jurisdiction of ASTM 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 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 onthe ASTM website.3C=CaO,S=SiO2,A=Al2O3,F=Fe2O3,S=SO3,M=MgO,N=Na2O,andK=K2O in cement 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 States1 3.3.3 periclase,ncrystalline form of free magnesium ox-ide(M),that has not been taken up in solid 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 sectioning 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-cou