ASTM C900-99
(Test Method)Standard Test Method for Pullout Strength of Hardened Concrete
Standard Test Method for Pullout Strength of Hardened Concrete
SCOPE
1.1 This test method covers determination of the pullout strength of hardened concrete by measuring the force required to pull an embedded metal insert and the attached concrete fragment from a concrete test specimen or structure. The insert is either cast into the fresh concrete or installed in hardened concrete.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information purposes only.
1.3 The text of this test method references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this test method.
1.4 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
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Standards Content (Sample)
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Designation: C 900 – 99
AMERICAN SOCIETY FOR TESTING AND MATERIALS
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Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Pullout Strength of Hardened Concrete
This standard is issued under the fixed designation C 900; 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.
1. Scope strengths can be related to compressive strength test results.
Such strength relationships depend on the configuration of the
1.1 This test method covers determination of the pullout
embedded insert, bearing ring dimensions, depth of embed-
strength of hardened concrete by measuring the force required
ment, and level of strength development in that concrete. Prior
to pull an embedded metal insert and the attached concrete
to use, these relationships must be established for each system
fragment from a concrete test specimen or structure. The insert
and each new combination of concreting materials. Such
is either cast into the fresh concrete or installed in hardened
relationships tend to be less variable where both pullout test
concrete.
specimens and compressive strength test specimens are of
1.2 The values stated in SI units are to be regarded as the
similar size, compacted to similar density, and cured under
standard. The values given in parentheses are for information
similar conditions.
purposes only.
1.3 The text of this test method references notes and
NOTE 1—Published reports (1-16) by different researchers present
footnotes which provide explanatory material. These notes and
their experiences in the use of pullout test equipment. Refer to ACI 228.1R
(14) for guidance on establishing a strength relationship and interpreting
footnotes (excluding those in tables and figures) shall not be
test results. The Appendix provides a means for comparing pull-out
considered as requirements of this test method.
strengths obtained using different configurations.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 4.2 Pullout tests are used to determine whether the in-place
strength of concrete has reached a specified level so that, for
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- example:
(1) post-tensioning may proceed;
bility of regulatory limitations prior to use.
(2) forms and shores may be removed; or
2. Referenced Documents
(3) winter protection and curing may be terminated.
2.1 ASTM Standards: In addition, post-installed pullout tests may be used to
C 39 Test Method for Compressive Strength of Cylindrical estimate the strength of concrete in existing constructions.
Concrete Specimens 4.3 When planning pullout tests and analyzing test results,
C 670 Practice for Preparing Precision and Bias Statements consideration should be given to the normally expected de-
for Test Methods for Construction Materials crease of concrete strength with increasing height within a
E 4 Practices for Force Verification of Testing Machines given concrete placement in a structural element. The mea-
sured pullout strength is indicative of the strength of concrete
3. Summary of Test Method
within the region represented by the conic frustum defined by
3.1 A metal insert is either case into fresh concrete or the insert head and bearing ring. For typical surface installa-
installed into hardened concrete. When an estimate of the
tions, pullout strengths are indicative of the quality of the outer
in-place strength is desired the insert is pulled by means of a zone of concrete members and can be of benefit in evaluating
jack reacting against a bearing ring. The pullout strength is
the cover zone of reinforced concrete members.
determined by measuring the maximum force required to pull 4.4 Cast-in-place inserts require that their locations in the
the insert from the concrete mass.
structure be planned in advance of concrete placement. Post-
installed inserts can be placed at any desired location in the
4. Significance and Use
structure provided the requirements of 6.1 are satisfied.
4.1 For a given concrete and a given test apparatus, pullout
4.5 This test method is not applicable to other types of
post-installed tests that, if tested to failure, do not involve the
This test method is under the jurisdiction of ASTM Committee C-9 on Concrete same failure mechanism and do not produce the same conic
and Concrete Aggregates and is the direct responsibility of Subcommittee C09.64 on
frustum as the cast-in-place test. (16).
Nondestructive and In-Place Testing .
Current edition approved June 10, 1999. Published July 1999. Originally
published as C 900 – 78 T. Last previous edition C 900 – 94. The boldface numbers refer to the list of references at the end of this test
Annual Book of ASTM Standards, Vol 04.02. method.
C 900
5. Apparatus
5.1 The apparatus requires three basic sub-systems: a pull-
out insert, a loading system, and a load-measuring system
(Note 2). For post-installed inserts, additional equipment
includes a core drill, a grinding wheel to prepare a flat bearing
surface, a milling tool to undercut a groove to engage the
insert, and an expansion tool to expand the insert into the
groove.
NOTE 2—A center-pull hydraulic jack with a suitable pressure gage and
bearing ring have been used satisfactorily.
5.1.1 Cast-in-place inserts shall be made of metal that does
not react with cement. The insert shall consist of a cylindrical
head and a shaft to fix embedment depth that is attached firmly
to the center of the head (see Fig. 1). The insert shaft shall be
threaded to the insert head so that it can removed and replaced
by a stronger shaft to pullout the insert, or it shall be an integral
part of the insert and also function as the pullout shaft. Metal
components of cast-in-place inserts and attachment hardware
shall be of similar material to prevent galvanic corrosion.
FIG. 2 Schematic of Procedure for Post-Installed Pullout Test
Post-installed inserts shall be designed so that they will fit into
the drilled holes, and can be expanded subsequently to fit into
the grooves that are undercut at a predetermined depth (see Fig.
shall be smooth (see Note 5). The insert head diameter shall be
2).
greater than or equal to ⁄3 of the nominal maximum size of
NOTE 3—A successful post-installed system uses a split ring that is aggregate.
coiled to fit into the core hole and then expanded into the groove.
NOTE 4—Typical insert diameters are 25 and 30 mm (1 and 1.2 in.), but
5.1.2 The loading system shall consist of a bearing ring to
larger diameters have been used (1, 3). Tests (15) have shown that nominal
be placed against the hardened concrete surface (see Figs. 1 maximum aggregate sizes up to 1.5 times the head diameter do not have
significant effects on the strength relationships. Larger aggregate sizes
and 2), and a loading apparatus with the necessary load-
may result in increased scatter of the test results because the particles can
measuring devices that can be readily attached to the pullout
restrict normal pullout of the conic frustum.
shaft.
NOTE 5—Cast-in–place inserts may be coated with a release agent to
5.1.3 The test apparatus shall include centering features to
minimize bonding with the concrete, and they may be tapered to minimize
ensure that the bearing ring is concentric with the insert, and
side friction during testing. The insert head should be provided with the
that the applied load is axial to the pullout shaft, perpendicular
means, such as a notch, to prevent rotation in the concrete if the insert
to the bearing ring, and uniform on the bearing ring. shaft has to be removed prior to performing the test. As a further
precaution against rotation of the insert head, all threaded hardware should
5.2 Equipment dimensions shall be determined as follows
be checked prior to installation to ensure that it is free-turning and can be
(see Figs. 1 and 2):
easily removed. A thread-lock compound is recommended to prevent
5.2.1 The diameter of the insert head (d ) is the basis for
loosening of the insert head from the shaft during installation and during
defining the test geometry. The thickness of the insert head and
vibration of the surrounding concrete.
the yield strength of the metal shall be sufficient to avoid
5.2.2 For cast-in–place inserts, the length of the pullout
yielding of the insert during test. The sides of the insert head
insert shaft shall be such that the distance from the insert head
to the concrete surface (h) equals the diameter of the insert
head (d ). The diameter of the insert shaft at the head (d ) shall
2 1
be no more than 0.60 times the head diameter.
5.2.3 For post-installed inserts, the groove to accept the
expandable insert shall be cut so that the distance between the
groove and concrete surface equals the insert diameter after
expansion (d ). The difference between the diameters of the
undercut groove and the core hole (d ) shall be sufficient to
prevent localized failure and ensure that a conic frustum is
extracted during the test (see Note 6). The expanded ring shall
bear uniformly on the entire bearing area of the groove.
NOTE 6—A core hole diameter of 18 mm (0.71 in.) and an undercut
groove diameter of 25 mm (1 in.) have been used successfully.
5.2.4 The bearing ring shall have an inside diameter (d )of
2.0 to 2.4 times the insert head diameter, and shall have an
FIG. 1 Schematic Cross Section of Cast-in-Place Pullout Test outside diameter (d ) of at least 1.25 times the inside diameter.
C 900
The thickness of the ring (t) shall be at least 0.4 times the same tests shall be embedded to the same depth and each shaft
pullout insert head diameter. shall be perpendicular to the formed surface.
5.2.5 Tolerances for dimensions of the pullout test inserts,
NOTE 11—Inserts may be manually placed into unformed horizontal
bearing ring and embedment depth shall be 62 % within a
concrete surfaces. The inserts should be embedded into the fresh concrete
given system.
by means that ensure a uniform embedment depth and a plane surface
perpendicular to the axis of the insert shaft. Installation of inserts should
NOTE 7—The limits for dimensions and configurations for pullout test
be performed or supervised by experienced personnel. Experience indi-
inserts and apparatus are intended to accommodate various systems.
cates that pullout strengths are of lower value and more variable for
5.2.6 The loading apparatus shall have sufficient capacity to manually-placed surface inserts than for inserts attached to the formwork.
provide the loading rate prescribed in 7.4 and exceed the
7.1.2 When the concrete is to be tested, remove all hardware
maximum load expected.
used for securing the pullout inserts in position. Before
NOTE 8—Hydraulic pumps that provide a constant loading rate may mounting the loading system, remove any debris or surface
give more uniform test results than pumps that apply the load intermit-
abnormalities to ensure a smooth bearing surface that is
tently.
perpendicular to the axis of the insert.
5.2.7 The gage to measure the pullout force shall have a 7.2 Post-Installed Inserts:
7.2.1 The selected test surface shall be flat to provide a
least division not larger than 5 % of the minimum value in the
intended range of use. suitable working surface for drilling the core and undercutting
the groove. Drill a core hole perpendicular to the surface to
NOTE 9—For the most accurate results, gages should have a maximum
provide a reference point for subsequent operations and to
value indicator that preserves the value of the ultimate load when ultimate
accommodate the expandable insert and associated hardware.
failure and subsequent stress release occur.
The use of an impact drill is not permitted.
5.2.8 Pullout apparatus shall be calibrated at least once a
7.2.2 If necessary, use a grinding wheel to prepare a flat
year and after all repairs or adjustments. Calibration shall be by
surface so that the base of the milling tool is supported firmly
one of the methods in Practices E 4, or with a compression
during test preparation and so that the bearing ring is supported
testing machine conforming to the requirements of Test
uniformly during testing. The ground surface shall be perpen-
Method C 39 using the calibration procedures described in the
dicular to the axis of the core hole.
Annex to this test method.
7.2.3 Use the milling tool to undercut a groove of the correct
diameter at the correct depth in the core hole. The groove shall
6. Sampling
be concentric with the core hole.
6.1 Pullout test locations shall be separated so that the clear
spacing between inserts is at least eight times the pullout insert NOTE 12—To control the accuracy of these operations, a support system
should be used to hold the apparatus in the proper position during these
head diameter. Clear spacing between the inserts and the edges
steps.
of the concrete shall be at least four times the head diameter.
Inserts shall be placed so that reinforcement is outside the
7.2.4 If water is used as a coolant, remove free-standing
expected conical failure surface by more than one bar diameter,
water from the hole at the completion of the drilling and
or the maximum size of aggregate, whichever is greater.
undercutting operations. Protect the hole from ingress of
additional water until the completion of the test.
NOTE 10—A reinforcement locator is recommended to assist in avoid-
ing reinforcement when preparing post-installed tests. Follow the manu-
NOTE 13—Penetration of water into the failure zone could affect the
facturer’s instructions for proper operation of such devices.
measured pullout strength; therefore, water must be removed from the
hole immediately after completion of drilling, grinding, and undercutting
6.2 When pullout test results are used to assess the in-place
operations. If the test will not be completed immediately after preparation
strength in order to allow the start of critical construction
of the hole, water must not be allowed to enter the hole before completing
operations, such as formwork removal or application of post
the test.
tensioning, at least five individual pullout tests shall be
7.2.5 Use the expansion tool to position the expandable
performed as follows:
3 3
insert into the groove and expand the insert to its proper size.
6.2.1 For a given placement, every 115 m (150 yd ), or a
7.3 Bearing Ring—Place
...
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