ASTM C805-97

Standard Test Method for Rebound Number of Hardened 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 SI units are to be regarded as 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: 09-Nov-1997
• 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

• Replaced By: ASTM C805-02 - Standard Test Method for Rebound Number of Hardened Concrete
• Effective Date: 10-Jul-2002

Standards Content (Sample)

ASTM-C805
ADOPTION NOTICE
ASTM-C805, "CONCRETE, HARDENED, REBOUND NUMBER OF", was adopted
on 23-MAY-94 for use by the Department of Defense (DoD).
Proposed changes by DoD activities must be submitted to the DoD
Adopting Activity: Commander, Defense Supply Center Philadelphia,
ATTN: DSCP-ILEA, 700 Robbins Avenue, Philadelphia, PA 19111-5096.
Copies of this document may be purchased from the American
Society for Testing and Materials 100 Barr Harbor Drive West
Conshohocken, Pennsylvania, United States, 19428-2959.
http://www.astm.org/____________________
Custodians: Adopting Activity:
Army - CR4 DLA - IS
Navy - YD
Air Force - 99
DLA - IS
Reviewer Activities:
Air Force - 84
FSC 5610
Approved for public release; distribution
DISTRIBUTION STATEMENT A:
is unlimited.

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Designation: C 805 – 97
Standard Test Method for
1
Rebound Number of Hardened Concrete
This standard is issued under the fixed designation C 805; 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 (e) indicates an editorial change since the last revision or reapproval.
This specification has been approved for use by agencies of the Department of Defense.
1. Scope numbers measured on the structure with the strengths of cores
3
taken from corresponding locations. See ACI 228. 1R for
1.1 This test method covers the determination of a rebound
additional information on developing the relationship and on
number of hardened concrete using a spring-driven steel
using the relationship to estimate in-place strength.
hammer.
4.3 For a given concrete mixture, the rebound number is
1.2 The values stated in SI units are to be regarded as the
affected by factors such as moisture content of the test surface,
standard.
the method used to obtain the test surface (type of form
1.3 This standard does not purport to address all of the
material or type of finishing), and the depth of carbonation.
safety concerns, if any, associated with its use. It is the
These factors need to be considered in preparing the strength
responsibility of the user of this standard to establish appro-
relationship and interpreting test results.
priate safety and health practices and determine the applica-
4.4 Because of the inherent uncertainty in the estimated
bility of regulatory limitations prior to use.
strength, this test method is not intended as the basis for
2. Referenced Documents
acceptance or rejection of concrete.
2.1 ASTM Standards:
5. Apparatus
E 177 Practice for Use of the Terms Precision and Bias in
2
5.1 Rebound Hammer, consisting of a spring-loaded steel
ASTM Test Methods
hammer which when released strikes a steel plunger in contact
3. Summary of Test Method
with the concrete surface. The spring-loaded hammer must
travel with a consistent and reproducible velocity. The rebound
3.1 A steel hammer impacts with a predetermined amount of
distance of the steel hammer from the steel plunger is measured
energy, a steel plunger in contact with a surface of concrete,
on a linear scale attached to the frame of the instrument.
and the distance that the hammer rebounds is measured.
NOTE 1—Several types and sizes of rebound hammers are commer-
4. Significance and Use
cially available to accommodate testing of various sizes and types of
4.1 This test method may be used to assess the in-place concrete construction.
uniformity of concrete, to delineate regions in a structure of
5.2 Abrasive Stone, consisting of medium-grain texture
poor quality or deteriorated concrete, and to estimate in-place
silicon carbide or equivalent material.
strength development.
5.3 Test Anvil, Approximately 150-mm (6-in.) diameter by
4.2 To use this test method to estimate strength requires
150-mm (6-in.) high cylinder made of tool steel with an impact
establishing a relationship between strength and rebound
area hardened to Brinell 500 or Rockwell 52 C. An instrument
number. The relationship shall be established for a given
guide is provided to center the rebound hammer over impact
concrete mixture and given apparatus. The relationship shall be
area and keep the instrument perpendicular to the surface.
established over the range of concrete strength that is of
interest. To estimate strength during construction, establish the 6. Test Area
relationship by performing rebound number tests on molded
6.1 Selection of Test Surface—Concrete members to be
specimens and measuring the strength of the same or compan-
tested shall be at least 100 mm (4 in.) thick and fixed within a
ion molded specimens. To estimate strength in an existing
structure. Smaller specimens must be rigidly supported. Areas
structure, establish the relationship by correlating rebound
exhibiting honeycombing, scaling, or high porosity should be
avoided. The form material against which the concrete was
placed should be sim
...