ASTM C805/C805M-08

Standard Test Method for Rebound Number of Hardened Concrete

SIGNIFICANCE AND USE
This test method is applicable to assess the in-place uniformity of concrete, to delineate regions in a structure of poorer quality or deteriorated concrete, and to estimate in-place strength.
Relationships between rebound number and concrete strength that are provided by instrument manufacturers shall be used only to provide indications of relative concrete strength at different locations in a structure. To use this test method to estimate strength, it is necessary to establish a relationship between strength and rebound number for a given concrete mixture and given apparatus. Establish the relationship by correlating rebound numbers measured on the structure with the strengths of cores taken from corresponding locations. At least two replicate cores shall be taken from at least six locations with different rebound numbers. Select test locations so that a wide range of rebound numbers in the structure is obtained. Obtain, moisture condition, and test cores in accordance with Test Method C 42/C 42M.
Note 1—See ACI 228.1R for additional information on developing the relationship and on using the relationship to estimate in-place strength.
For a given concrete mixture, the rebound number is affected by factors such as moisture content of the test surface, the method used to obtain the test surface (type of form material or type of finishing), vertical distance from the bottom of a concrete placement, and the depth of carbonation. These factors need to be considered in interpreting rebound numbers.
Different hammers of the same nominal design may give rebound numbers differing from 1 to 3 units. Therefore, tests should be made with the same hammer in order to compare results. If more than one hammer is to be used, perform tests on a range of typical concrete surfaces so as to determine the magnitude of the differences to be expected.
This test method is not suitable as the basis for acceptance or rejection of concrete.
SCOPE
1.1 This test method covers the determination of a rebound number of hardened concrete using a spring-driven steel hammer.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.3 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.

General Information

• Status: Historical
• Publication Date: 31-Jul-2008
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: C09 - Concrete and Concrete Aggregates
• Drafting Committee: C09.64 - Nondestructive and In-Place Testing

Relations

• Replaces: ASTM C805-02 - Standard Test Method for Rebound Number of Hardened Concrete
• Effective Date: 01-Aug-2008
• Replaced By: ASTM C805/C805M-13 - Standard Test Method for Rebound Number of Hardened Concrete
• Effective Date: 01-Jan-2013
• Referred By: ASTM C1903-21 - Standard Specification for Precast Concrete Duct Bank
• Effective Date: 01-Aug-2008

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C805/C805M − 08
StandardTest Method for
1
Rebound Number of Hardened Concrete
This standard is issued under the fixed designation C805/C805M; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope* 4. Summary of Test Method
1.1 This test method covers the determination of a rebound 4.1 A steel hammer impacts, with a predetermined amount
number of hardened concrete using a spring-driven steel of energy, a steel plunger in contact with a surface of concrete,
hammer. and the distance that the hammer rebounds is measured.
1.2 The values stated in either SI units or inch-pound units
5. Significance and Use
are to be regarded separately as standard. The values stated in
5.1 This test method is applicable to assess the in-place
each system may not be exact equivalents; therefore, each
uniformity of concrete, to delineate regions in a structure of
system shall be used independently of the other. Combining
poorerqualityordeterioratedconcrete,andtoestimatein-place
values from the two systems may result in non-conformance
strength.
with the standard.
5.2 Relationships between rebound number and concrete
1.3 This standard does not purport to address all of the
strengththatareprovidedbyinstrumentmanufacturersshallbe
safety concerns, if any, associated with its use. It is the
used only to provide indications of relative concrete strength at
responsibility of the user of this standard to establish appro-
different locations in a structure. To use this test method to
priate safety and health practices and determine the applica-
estimate strength, it is necessary to establish a relationship
bility of regulatory limitations prior to use.
between strength and rebound number for a given concrete
mixture and given apparatus. Establish the relationship by
2. Referenced Documents
correlating rebound numbers measured on the structure with
2
2.1 ASTM Standards:
the strengths of cores taken from corresponding locations. At
C42/C42M Test Method for Obtaining and Testing Drilled
least two replicate cores shall be taken from at least six
Cores and Sawed Beams of Concrete
locations with different rebound numbers. Select test locations
C125 Terminology Relating to Concrete and Concrete Ag-
so that a wide range of rebound numbers in the structure is
gregates
obtained. Obtain, moisture condition, and test cores in accor-
C670 Practice for Preparing Precision and Bias Statements
dance with Test Method C42/C42M.
for Test Methods for Construction Materials 3
NOTE1—SeeACI228.1R foradditionalinformationondevelopingthe
E18 Test Methods for Rockwell Hardness of Metallic Ma-
relationship and on using the relationship to estimate in-place strength.
terials
5.3 For a given concrete mixture, the rebound number is
affected by factors such as moisture content of the test surface,
3. Terminology
the method used to obtain the test surface (type of form
3.1 Definitions:
material or type of finishing), vertical distance from the bottom
3.1.1 For definitions of terms used in this test method, refer
of a concrete placement, and the depth of carbonation. These
to Terminology C125.
factors need to be considered in interpreting rebound numbers.
5.4 Differenthammersofthesamenominaldesignmaygive
rebound numbers differing from 1 to 3 units. Therefore, tests
1
This test method is under the jurisdiction of ASTM Committee C09 on
should be made with the same hammer in order to compare
Concrete and ConcreteAggregates and is the direct responsibility of Subcommittee
results.Ifmorethanonehammeristobeused,performtestson
C09.64 on Nondestructive and In-Place Testing.
a range of typical concrete surfaces so as to determine the
Current edition approved Aug. 1, 2008. Published September 2008. Originally
approved in 1975. Last previous edition approved in 2002 as C805 – 02. DOI: magnitude of the differences to be expected.
10.1520/C0805_C0805M-08.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
3
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM ACI 228.1R-95, “In-Place Methods to Estimate Concrete Strength,” American
Standards volume information, refer to the standard’s Document Summary page on Concrete Institute (ACI), P.O. Box 9094, Farmington Hills, MI 48333-9094,
the ASTM website. http://www.concrete.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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This document is not an ASTM standard and is intended only to provide the user of an ASTM 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:C805–02 Designation:C805/C805M–08
Standard Test Method for
1
Rebound Number of Hardened Concrete
This standard is issued under the fixed designation C 805/C 805M; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope*
1.1 This test method covers the determination of a rebound number of hardened concrete using a spring-driven steel hammer.
1.2The values stated in SI units are to be regarded as the standard.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the
two systems may result in non-conformance with the standard.
1.3 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.
2. Referenced Documents
2
2.1 ASTM Standards:
C 42/C 42M Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
C 125 Terminology Relating to Concrete and Concrete Aggregates
C 670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
E 18 Test Methods for Rockwell and Rockwell Superficial Hardness of Metallic Materials
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer to Terminology C 125.
4. Summary of Test Method
4.1 Asteel hammer impacts, with a predetermined amount of energy, a steel plunger in contact with a surface of concrete, and
the distance that the hammer rebounds is measured.
5. Significance and Use
5.1This test method is applicable to assess the in-place uniformity of concrete, to delineate regions in a structure of poor quality
or deteriorated concrete, and to estimate in-place strength development.
5.2To use this test method to estimate strength requires establishing a relationship between strength and rebound number. The
relationship shall be established for a given concrete mixture and given apparatus. The relationship shall be established over the
range of concrete strength that is of interest. To estimate strength during construction, establish the relationship by performing
rebound number tests on molded specimens and measuring the strength of the same or companion molded specimens. To estimate
strength in an existing structure, establish the relationship by correlating rebound numbers measured on the structure with the
strengths of cores taken from corresponding locations. See ACI 228.1R
5.1 This test method is applicable to assess the in-place uniformity of concrete, to delineate regions in a structure of poorer
quality or deteriorated concrete, and to estimate in-place strength.
5.2 Relationships between rebound number and concrete strength that are provided by instrument manufacturers shall be used
only to provide indications of relative concrete strength at different locations in a structure. To use this test method to estimate
1
This test method is under the jurisdiction ofASTM Committee C09 on Concrete and ConcreteAggregates and is the direct responsibility of Subcommittee C09.64 on
Nondestructive and In-Place Testing .
Current edition approved July 10, 2002. Published August 2002. Originally published as C805–75T. Last previous edition C805–97.
Current edition approved Aug. 1, 2008. Published September 2008. Originally approved in 1975. Last previous edition approved in 2002 as C 805 – 02.
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
, Vol 04.02.volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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C805/C805M–08
strength, it is necessary to establish a relationship between strength and rebound number for a given concre
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