Designation: C856 − 17Standard Practice forPetrographic Examination of Hardened Concrete 1This standard is issued under the f i xed designation C856; 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 practice outlines procedures for the petrographicexamination of samples of hardened concrete. The samplesexamined may be taken from concrete constructions, they maybe concrete products or portions thereof, or they may beconcrete or mortar specimens that have been exposed in naturalenvironments, or to simulated service conditions, or subjectedto laboratory tests. The phrase “concrete constructions” isintended to include all sorts of objects, units, or structures thathave been built of hydraulic cement concrete.N OTE 1—A photographic chart of materials, phenomena, and reactionproducts discussed in Sections 8 – 13 and Tables 1-6 are available asAdjunct C856 (ADJCO856).1.2 The petrographic procedures outlined herein are appli-cable to the examination of samples of all types of hardenedhydraulic-cement mixtures, including concrete, mortar, grout,plaster, stucco, terrazzo, and the like. In this practice, thematerial for examination is designated as “concrete,” eventhough the commentary may be applicable to the othermixtures, unless the reference is specif i cally to media otherthan concrete.1.3 The purposes of and procedures for petrographic exami-nation of hardened concrete are given in the following sections:SectionQualif i cations of Petrographers and Use of Technicians 4Purposes of Examination 5Apparatus 6Selection and Use of Apparatus 7Samples 8Examination of Samples 9Specimen Preparation 10Visual and Stereomicroscope Examination 11Polarizing Microscope Examination 12Paste Features 13Report 141.4 The values stated in inch-pound units are to be regardedas the standard. The SI units in parentheses are provided forinformation purposes only.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. A specif i c hazardstatement is given in 6.2.10.1.2. Referenced Documents2.1 ASTM Standards: 2C125 Terminology Relating to Concrete and Concrete Ag-gregatesC215 Test Method for Fundamental Transverse,Longitudinal, and Torsional Resonant Frequencies ofConcrete SpecimensC227 Test Method for Potential Alkali Reactivity ofCement-Aggregate Combinations (Mortar-Bar Method)C342 Test Method for Potential Volume Change of Cement-Aggregate Combinations (Withdrawn 2001) 3C441 Test Method for Effectiveness of Pozzolans or GroundBlast-Furnace Slag in Preventing Excessive Expansion ofConcrete Due to the Alkali-Silica ReactionC452 Test Method for Potential Expansion of Portland-Cement Mortars Exposed to SulfateC457 Test Method for Microscopical Determination of Pa-rameters of the Air-Void System in Hardened ConcreteC496/C496M Test Method for Splitting Tensile Strength ofCylindrical Concrete SpecimensC597 Test Method for Pulse Velocity Through ConcreteC803/C803M Test Method for Penetration Resistance ofHardened ConcreteC805 Test Method for Rebound Number of Hardened Con-creteC823 Practice for Examination and Sampling of HardenedConcrete in ConstructionsC1012 Test Method for Length Change of Hydraulic-Cement Mortars Exposed to a Sulfate SolutionC1260 Test Method for Potential Alkali Reactivity of Ag-gregates (Mortar-Bar Method)1 This practice is under the jurisdiction of ASTM Committee C09 on Concreteand ConcreteAggregates and is the direct responsibility of Subcommittee C09.65 onPetrography.Current edition approved Jan. 1, 2017. Published March 2017. Originallyapproved in 1977. Last previous edition approved in 2014 as C856 – 14. DOI:10.1520/C0856-17.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service@astm.org. For Annual Book of ASTMStandards volume information, refer to the standard’s Document Summary page onthe ASTM website.3 The 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 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.1 Copyright by ASTM Int'l (all rights reserved); Sat Oct 7 00:16:25 EDT 2017Downloaded/printed byUniversity of Edinburgh (University of Edinburgh) pursuant to License Agreement. No further reproductions authorized.
