ASTM C856-11
(Practice)Standard Practice for Petrographic Examination of Hardened Concrete
Standard Practice for Petrographic Examination of Hardened Concrete
ABSTRACT
This practice outlines the standard procedures for performing petrographic examination of hardened concrete samples. The samples examined may be taken from concrete constructions, that is, all sorts of objects, units, or structures that have been built of hydraulic cement concrete. They may also be concrete products or portions thereof, or concrete or mortar specimens that have been exposed in natural environments or simulated service conditions, or subjected to laboratory tests. This practice applies to samples of all types of hardened hydraulic-cement mixtures, including concrete, mortar, grout, plaster, stucco, terrazzo, and the like. The equipments generally used for specimen preparation are diamond saw, cutting lubricant, horizontal lap wheels, free abrasive machine, polishing wheel, hot plate or oven, prospector's pick and/or bricklayer's hammer, abrasives, plate-glass squares, suitable media, and microscope slides. For specimen examination, the equipments needed are stereomicroscope, dollies, petrographic or polarizing microscope, metallographic microscope, eyepiece micrometer, stage micrometer, microscope lamps, needleholders and points, bottles with droppers, assorted forceps, lens paper, refractometer, and immersion media. Appropriate procedures for the sampling, preparation, and examination of specimens are detailed methodically.
SCOPE
1.1 This practice outlines procedures for the petrographic examination of samples of hardened concrete. The samples examined may be taken from concrete constructions, they may be concrete products or portions thereof, or they may be concrete or mortar specimens that have been exposed in natural environments, or to simulated service conditions, or subjected to laboratory tests. The phrase “concrete constructions” is intended to include all sorts of objects, units, or structures that have been built of hydraulic cement concrete.
Note 1—A photographic chart of materials, phenomena, and reaction products discussed in Sections 8-13 and Tables 1-6 are available as Adjunct C856 (ADJCO856).
1.2 The petrographic procedures outlined herein are applicable to the examination of samples of all types of hardened hydraulic-cement mixtures, including concrete, mortar, grout, plaster, stucco, terrazzo, and the like. In this practice, the material for examination is designated as “concrete,” even though the commentary may be applicable to the other mixtures, unless the reference is specifically to media other than concrete.
1.3 Annex A1 outlines an uranyl acetate method for identifying locations where alkali-silica gel may be present. It is a requirement that the substances in those locations must be identified using any other more definitive techniques, such as petrographic microscopy.
1.4 The purposes of and procedures for petrographic examination of hardened concrete are given in the following sections:
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Designation: C856 − 11
StandardPractice for
1
Petrographic Examination of Hardened Concrete
This standard is issued under the fixed designation C856; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
Section
1.1 This practice outlines procedures for the petrographic
Qualifications of Petrographers and Use of Technicians 4
Purposes of Examination 5
examination of samples of hardened concrete. The samples
Apparatus 6
examined may be taken from concrete constructions, they may
Selection and Use of Apparatus 7
be concrete products or portions thereof, or they may be
Samples 8
Examination of Samples 9
concreteormortarspecimensthathavebeenexposedinnatural
Specimen Preparation 10
environments, or to simulated service conditions, or subjected
Visual and Stereomicroscope Examination 11
to laboratory tests. The phrase “concrete constructions” is
Polarizing Microscope Examination 12
Paste Features 13
intended to include all sorts of objects, units, or structures that
Report 14
have been built of hydraulic cement concrete.
1.5 Thevaluesstatedininch-poundunitsaretoberegarded
NOTE 1—A photographic chart of materials, phenomena, and reaction
as the standard. The SI units in parentheses are provided for
products discussed in Sections 8-13 and Tables 1-6 are available as
information purposes only.
Adjunct C856 (ADJCO856).
1.6 This standard does not purport to address all of the
1.2 The petrographic procedures outlined herein are appli-
safety concerns, if any, associated with its use. It is the
cable to the examination of samples of all types of hardened
responsibility of the user of this standard to establish appro-
hydraulic-cement mixtures, including concrete, mortar, grout,
priate safety and health practices and determine the applica-
plaster, stucco, terrazzo, and the like. In this practice, the
bility of regulatory limitations prior to use. A specific hazard
material for examination is designated as “concrete,” even
statement is given in 6.2.10.1.
though the commentary may be applicable to the other
mixtures, unless the reference is specifically to media other
2. Referenced Documents
than concrete.
2
2.1 ASTM Standards:
1.3 AnnexA1 outlines an uranyl acetate method for identi-
C125Terminology Relating to Concrete and Concrete Ag-
fying locations where alkali-silica gel may be present. It is a
gregates
requirement that the substances in those locations must be
C215 Test Method for Fundamental Transverse,
identified using any other more definitive techniques, such as
Longitudinal, and Torsional Resonant Frequencies of
petrographic microscopy.
Concrete Specimens
C227 Test Method for Potential Alkali Reactivity of
1.4 Thepurposesofandproceduresforpetrographicexami-
Cement-Aggregate Combinations (Mortar-Bar Method)
nationofhardenedconcretearegiveninthefollowingsections:
C342Test Method for PotentialVolume Change of Cement-
3
Aggregate Combinations (Withdrawn 2001)
C441TestMethodforEffectivenessofPozzolansorGround
1
This practice is under the jurisdiction of ASTM Committee C09 on Concrete
andConcreteAggregatesandisthedirectresponsibilityofSubcommitteeC09.65on
2
Petrography. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2011. Published April 2011. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1977. Last previous edition approved in 2004 as C856–04. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/C0856-11. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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C856 − 11
6
TABLE 1 Visual Examination of Concrete (1)
Coarse Aggregate + Fine Aggregate + Matrix + Air + Embedded Items
Composition:
A
Maximum dimension, in. or
mm, in the range> d>
Type: Type: color, by comparison with more than 3 % of total, Type, size, location;
National Research kinds of metal; other
Council Rock Color items
Chart (1963)
1 Gravel 1 Natural sand predominantly in spherical
2 Crushed stone 2 Manufactured sand color distribution: voids?
3 Mixed 1 and 2 3 Mixed 1 mottled less than 3 % of total,
4 Other (name) 4 Other (name) 2 even abundant nonspherical
5 Mixed 1 + /or 2 + /or 4 5 Mixed 1 + /or 2 + /or 4 3 gradational changes voids?
If Type 1, 2, or 4, homogeneous If Type 1, 2, or 4, color differences between
or heterogeneous homogeneous or voids and mortar?
heterogeneous
Lithologic types voids empty, filled, lined, or
Coarse aggregate more than 20, partly fi
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:C856–04 Designation:C856–11
Standard Practice for
1
Petrographic Examination of Hardened Concrete
This standard is issued under the fixed designation C856; the number immediately following the designation indicates the year of
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.
1. Scope
1.1 This practice outlines procedures for the petrographic examination of samples of hardened concrete.The samples examined
may be taken from concrete constructions, they may be concrete products or portions thereof, or they may be concrete or mortar
specimens that have been exposed in natural environments, or to simulated service conditions, or subjected to laboratory tests.The
phrase “concrete constructions” is intended to include all sorts of objects, units, or structures that have been built of hydraulic
cement concrete.
NOTE 1—Aphotographic chart of materials, phenomena, and reaction products discussed in Sections 7-12 8-13 andTables 1-6 are available asAdjunct
C856 (ADJCO856).
1.2 The petrographic procedures outlined herein are applicable to the examination of samples of all types of hardened
hydraulic-cement mixtures, including concrete, mortar, grout, plaster, stucco, terrazzo, and the like. In this practice, the material
for examination is designated as “concrete,” even though the commentary may be applicable to the other mixtures, unless the
reference is specifically to media other than concrete.
1.3 Annex A1 outlines an uranyl acetate method for identifying locations where alkali-silica gel may be present. It is a
requirement that the substances in those locations must be identified using any other more definitive techniques, such as
petrographic microscopy.
1.4 The purposes of and procedures for petrographic examination of hardened concrete are given in the following sections:
Section
Qualifications of Petrographers and Use of Technicians 3
Qualifications of Petrographers and Use of Technicians 4
Purposes of Examination 4
Purposes of Examination 5
Apparatus 5
Apparatus 6
Selection and Use of Apparatus 6
Selection and Use of Apparatus 7
Samples 7
Samples 8
Examination of Samples 8
Examination of Samples 9
Specimen Preparation 9
Specimen Preparation 10
Visual and Stereomicroscope Examination 10
Visual and Stereomicroscope Examination 11
Polarizing Microscope Examination 11
Polarizing Microscope Examination 12
Paste Features 12
Paste Features 13
Report 13
Report 14
1.5 The values stated in inch-pound units are to be regarded as the standard. The SI units in parentheses are provided for
information purposes only.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use. A specific hazard statement is given in 5.2.10.16.2.10.1.
1
This practice is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.65 on
Petrography.
Current edition approved Jan.April 1, 2004.2011. Published February 2004.April 2011. Originally approved in 1977. Last previous edition approved in 20022004 as
C856–02.C856–04. DOI: 10.1520/C0856-04.10.1520/C0856-11.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
---------------------- Page: 1 ----------------------
C856–11
6
TABLE 1 Visual Examination of Concrete (1)
Coarse Aggregate + Fine Aggregate + Matrix + Air + Embedded Items
Composition:
A
Maximum dimension, in. or
mm, in the range> d>
Type: Type: color, by comparison with more than 3 % of total, Type, size, location;
National Research kinds of metal; other
Council Rock Color items
Chart (1963)
1 Gravel 1 Natural sand predominantly in spherical
2 Crushed stone 2 Manufactured sand color distribution: voids?
3 Mixed 1 and 2 3 Mixed 1 mottled less than 3 % of total,
4 Other (name) 4 Other (name) 2 even abundant nonspherical
5 Mixed 1 + /or 2 + /or 4 5 Mixed 1 + /or 2 + /or 4 3 gradational changes voids?
If Type 1, 2, or 4, homogeneous If Type 1, 2, or 4, color differences between
or heterogeneous homogeneous or voids and mortar?
heterogeneous
Lithologic types voids empty, filled, lined, or
Coarse aggregate more than 20, partly filled
30, 40, or 50 % of total
Fab
...
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