ASTM_C_295_-_C_295M_-_12.pdf

Designation:C295/C295M12Standard Guide forPetrographic Examination of Aggregates for Concrete1This standard is issued under the fixed designation C295/C295M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1.Scope*1.1 This guide outlines procedures for the petrographicexamination of samples representative of materials proposedfor use as aggregates in cementitious mixtures or as rawmaterials for use in production of such aggregates.This guideis based on Ref(1).21.2 This guide outlines the extent to which petrographictechniques should be used,the selection of properties thatshould be looked for,and the manner in which such techniquesmay be employed in the examination of samples of aggregatesfor concrete.1.3 The rock and mineral names given in DescriptiveNomenclature C294 should be used,insofar as they areappropriate,in reports prepared in accordance with this guide.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.5 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.2.Referenced Documents2.1 ASTM Standards:3C33 Specification for Concrete AggregatesC117 Test Method for Materials Finer than 75-m(No.200)Sieve in Mineral Aggregates by WashingC136 Test Method for Sieve Analysis of Fine and CoarseAggregatesC294 Descriptive Nomenclature for Constituents of Con-crete AggregatesC702 Practice for Reducing Samples ofAggregate to TestingSizeD75 Practice for Sampling AggregatesE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE883 Guide for ReflectedLight Photomicrography3.Qualifications of Petrographers3.1 All petrographic examinations of aggregate for use inconcrete as described in this guide should be performed by apetrographer with at least 5 years experience in petrographicexamination of concrete or concrete-making materials.Thepetrographer should have completed college-level course workpertaining to basic geology,mineralogy,petrography,andoptical mineralogy or have obtained equivalent knowledgethrough experience and on-the-job training.Completion ofcourse work in concrete materials is also advantageous.Thepetrographer should have experience evaluating the effects ofaggregates on the physical and chemical properties of hardenedconcrete.Identification of individual minerals in aggregateparticles,classification of rock types,and categorizing thephysical and chemical properties of rocks and minerals shouldalso be included in the petrographers experience.The petrog-rapher should have expertise to properly use the equipment andapparatus described in Section 6 and provide detailed interpre-tations of the petrographic examination.If the petrographerdoes not meet these qualifications,the individual may performsuch examinations under the technical direction of a full-timesupervising petrographer who meets these qualifications.Aresume of the professional experience and education of thepetrographer shall be available.3.1.1 Licensing,certification,or other accreditation by agovernmental agency or other organization stating the indi-vidual is a professional geologist should not,by itself,consti-tute sufficient qualification for examination of aggregates forconcrete.1This guide is under the jurisdiction of ASTM Committee C09 on Concrete andConcrete Aggregates and is the direct responsibility of Subcommittee C09.65 onPetrography.Current edition approved April 1,2012.Published May 2012.Originallyapproved in 1954.Last previous edition approved in 2011 as C295/C295M11.DOI:10.1520/C0295_C0295M-12.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.3For 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.*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 4.Summary of Method4.1 The specific procedures employed in the petrographicexamination of any sample will depend to a large extent on thepurpose of the examination and the nature of the sample.Inmost cases the examination will require t