ASTM C78-00

Standard Test Method for Flexural Strength of Concrete (Using Simple Beam with Third-Point Loading)

SCOPE
1.1 This test method covers the determination of the flexural strength of concrete by the use of a simple beam with third-point loading.
1.2 The values stated in inch-pound units are to be regarded as the standard. The SI equivalent of inch-pound units has been rounded where necessary for practical application.
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-Jan-2002
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: C09 - Concrete and Concrete Aggregates
• Drafting Committee: C09.61 - Testing for Strength

Relations

• Replaces: ASTM C78-94 - Standard Test Method for Flexural Strength of Concrete (Using Simple Beam with Third-Point Loading)
• Effective Date: 10-Jan-2002
• Replaced By: ASTM C78-02 - Standard Test Method for Flexural Strength of Concrete (Using Simple Beam with Third-Point Loading)
• Effective Date: 10-Jan-2002
• Referred By: ASTM C928/C928M-20a - Standard Specification for Packaged, Dry, Rapid-Hardening Cementitious Materials for Concrete Repairs
• Effective Date: 10-Jan-2002
• Referred By: ASTM C651-20 - Standard Test Method for Flexural Strength of Manufactured Carbon and Graphite Articles Using Four-Point Loading at Room Temperature
• Effective Date: 10-Jan-2002
• Referred By: ASTM D7972-14(2020) - Standard Test Method for Flexural Strength of Manufactured Carbon and Graphite Articles Using Three-Point Loading at Room Temperature
• Effective Date: 10-Jan-2002
• Referred By: ASTM D7958/D7958M-17 - Standard Test Method for Evaluation of Performance for FRP Composite Bonded to Concrete Substrate using Beam Test
• Effective Date: 10-Jan-2002
• Referred By: ASTM C1399/C1399M-10(2015) - Standard Test Method for Obtaining Average Residual-Strength of Fiber-Reinforced Concrete
• Effective Date: 10-Jan-2002
• Referred By: ASTM C688-22 - Standard Specification for Functional Additions for Use in Hydraulic Cements
• Effective Date: 10-Jan-2002

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: C 78 – 00
Standard Test Method for
Flexural Strength of Concrete (Using Simple Beam with
1
Third-Point Loading)
This standard is issued under the fixed designation C 78; 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 standard has been approved for use by agencies of the Department of Defense.
1. Scope beam has been molded or sawed to size.
3.2 The results of this test method may be used to determine
1.1 This test method covers the determination of the flexural
compliance with specifications or as a basis for proportioning,
strength of concrete by the use of a simple beam with
mixing and placement operations. It is used in testing concrete
third-point loading.
for the construction of slabs and pavements (Note 1).
1.2 The values stated in inch-pound units are to be regarded
as the standard. The SI equivalent of inch-pound units has been
4. Apparatus
rounded where necessary for practical application.
4.1 The testing machine shall conform to the requirements
1.3 This standard does not purport to address all of the
of the sections on Basis of Verification, Corrections, and Time
safety concerns, if any, associated with its use. It is the
Interval Between Verifications of Practices E 4. Hand operated
responsibility of the user of this standard to establish appro-
testing machines having pumps that do not provide a continu-
priate safety and health practices and determine the applica-
ous loading in one stroke are not permitted. Motorized pumps
bility of regulatory limitations prior to use.
or hand operated positive displacement pumps having suffi-
2. Referenced Documents cient volume in one continuous stroke to complete a test
without requiring replenishment are permitted and shall be
2.1 ASTM Standards:
capable of applying loads at a uniform rate without shock or
C 31 Practice for Making and Curing Concrete Test Speci-
2
interruption.
mens in the Field
4.2 Loading Apparatus—The third point loading method
C 42 Test Method for Obtaining and Testing Drilled Cores
2
shall be used in making flexure tests of concrete employing
and Sawed Beams of Concrete
bearing blocks which will ensure that forces applied to the
C 192 Practice for Making and Curing Concrete Test Speci-
2
beam will be perpendicular to the face of the specimen and
mens in the Laboratory
applied without eccentricity. A diagram of an apparatus that
C 617 Practice for Capping Cylindrical Concrete Speci-
2
accomplishes this purpose is shown in Fig. 1.
mens
4.2.1 All apparatus for making flexure tests of concrete shall
C 1077 Practice for Laboratories Testing Concrete and Con-
be capable of maintaining the specified span length and
crete Aggregates for Use in Construction and Criteria for
2
distances between load-applying blocks and support blocks
Laboratory Evaluation
3 constant within 60.05 in. (61.3 mm).
E 4 Practices for Force Verification of Testing Machines
4.2.2 Reactions shall be parallel to the direction of the
3. Significance and Use applied forces at all times during the test and the ratio of
distance between the point of load application and nearest
3.1 This test method is used to determine the flexural
reaction to the depth of the beam shall not be less than one.
strength of specimens prepared and cured in accordance with
4.2.3 If an apparatus similar to that illustrated in Fig. 1 is
Test Methods C 42 or Practices C 31 or C 192. Results are
used: the load-applying and support blocks should not be more
calculated and reported as the modulus of rupture. The strength
1
than 2 ⁄2 in. (64 mm) high, measured from the center or the axis
determined will vary where there are differences in specimen
of pivot, and should extend entirely across or beyond the full
size, preparation, moisture condition, curing, or where the
width of the specimen. Each case-hardened bearing surface in
contact with the specimen shall not depart from a plane by
1
This test method is under the jurisdiction of ASTM Committee C09 on
more than 0.002 in. (0.05 mm) and shall be a portion of a
Concrete and Concrete Aggregatesand is the direct responsibility of Subcommittee
cylinder, the axis of which is coincidental with either the axis
C09.61on Testing Concrete for Strength.
Current edition approved Dec. 10, 2000. Published June 2001. Originally of the rod or center of the ball, whichever the block is pivoted
published as C 78 – 30T. Last previous edition C 78 – 94.
upon. The angle subtended by the curved surface of each block
2
Annual Book of ASTM Standards, Vol 04.02.
should be at least 45° (0.79 rad). The load-applying and
3
Annual Book of ASTM Standards, Vol
...