ASTM C580-18(2023)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C580 − 18 (Reapproved 2023)
Standard Test Method for
Flexural Strength and Modulus of Elasticity of Chemical-
Resistant Mortars, Grouts, Monolithic Surfacings, and
Polymer Concretes
This standard is issued under the fixed designation C580; 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 U.S. Department of Defense.
1. Scope mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This test method covers the determination of flexural
strength and modulus of elasticity in flexure of cured chemical-
2. Referenced Documents
resistant materials in the form of molded rectangular beams.
2.1 ASTM Standards:
These materials include mortars, brick and tile grouts, struc-
C904 Terminology Relating to Chemical-Resistant Nonme-
tural grouts, machinery grouts, monolithic surfacings (60 mils
tallic Materials
or greater), and polymer concretes. These materials shall be
C1312 Practice for Making and Conditioning Chemical-
based on resin, silicate, silica, or sulfur binders.
Resistant Sulfur Polymer Cement Concrete Test Speci-
1.2 A bar of rectangular cross section is tested in flexure as
mens in the Laboratory (Withdrawn 2021)
a simple beam in center point loading: the bar rests on two
E4 Practices for Force Calibration and Verification of Test-
supports and the load is applied by means of a loading nose
ing Machines
midway between supports.
E177 Practice for Use of the Terms Precision and Bias in
1.3 Method A outlines the testing procedure generally used
ASTM Test Methods
for systems containing aggregate less than 0.2 in. (5 mm) in
E691 Practice for Conducting an Interlaboratory Study to
size. Method B covers the testing procedure generally used for
Determine the Precision of a Test Method
systems containing aggregate from 0.2 in. to 0.4 in. (10 mm) in
size. Method C is used for systems containing aggregate larger
3. Terminology
than 0.4 in.
3.1 Definitions—For definitions of terms used in this test
1.4 The values stated in inch-pound units are to be regarded method, see Terminology C904.
as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only 4. Significance and Use
and are not considered standard.
4.1 This test method is generally applicable to rigid and
1.5 This standard does not purport to address all of the semirigid materials. Although flexural strength cannot be
safety concerns, if any, associated with its use. It is the determined for those materials that do not break, tangent
responsibility of the user of this standard to establish appro- modulus of elasticity can be determined.
priate safety, health, and environmental practices and deter-
4.2 The results obtained by this test method should serve as
mine the applicability of regulatory limitations prior to use.
a guide in, but not as the sole basis for, selection of a
1.6 This international standard was developed in accor-
chemical-resistant material for a particular application. No
dance with internationally recognized principles on standard-
attempt has been made to incorporate into this test method all
ization established in the Decision on Principles for the
the various factors that may affect the performance of a
Development of International Standards, Guides and Recom-
material when subjected to actual service.
1 2
This test method is under the jurisdiction of ASTM Committee D01 on Paint For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and Related Coatings, Materials, and Applications and is the direct responsibility of contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Subcommittee D01.46 on Industrial Protective Coatings. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved June 1, 2023. Published June 2023. Originally the ASTM website.
approved in 1965. Last previous edition approved in 2018 as C580 – 18. DOI: The last approved version of this historical standard is referenced on
10.1520/C0580-18R23. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C580 − 18 (2023)
4.3 In addition to the tangent modulus of elasticity, a secant 6. Test Specimens
modulus is calculated at the point on the stress-strain (load-
6.1 All specimens for a single determination shall be made
deflection) graph where the strain is 50 % of the maximum
from a single mix containing sufficient amounts of the com-
strain.
ponents in the proportions and in the manner specified by the
manufacturer of the materials. If the proportions so specified
5. Apparatus
are by volume, the components shall be weighed and the
corresponding proportions by weight shall be reported.
5.1 Weighing Equipment, shall be capable of weighing
6.1.1 Number of Specimens—Prepare a minimum of six test
materials or specimens to 60.3 % accuracy.
bar specimens for each material tested. Additional specimens
5.2 Equipment for Mixing Materials, shall consist of a
may be required to establish the cross head speed in 9.3.2.
container of suitable size, preferably corrosion-resistant, a
3 6.2 Specimen Size:
spatula, trowel, or mechanical mixer, and a ⁄8 in. diameter rod
6.2.1 For Method A, the specimen shall be 1 in. 6 ⁄16 in.
with a rounded end, for use in casting specimens.
(25 mm 6 1 mm) square by 10 in. to 14 in. (254 mm to
5.3 Specimen Molds:
356 mm) long.
5.3.1 Method A—Molds to permit the casting of bars 1 in. 6
6.2.2 For Method B, the specimens shall be 2 in. 6 ⁄8 in.
⁄16 in. (25 mm 6 1 mm) square by 10 in. (250 mm) minimum
(25 mm 6 1 mm) square by 12 in. to 16 in. (305 mm to
length.
406 mm) long.
5.3.1.1 For sulfur mortars, the following additional equip-
6.2.3 For Method C, the specimens shall be rectangular
ment is required:
beams with cross section as in 5.3.3 and with a length equal to
(1) Cover Plate, of a size sufficient to enclose the open side
the span plus 2 in. to 12 in. (51 mm to 305 mm).
of the bar mold. The base plate from another similar bar mold
6.3 Specimen Preparation Temperature:
has been found to be acceptable.
6.3.1 Resin, Silicate, and Silica Materials—The standard
(2) C-Clamp, large enough to fasten the cover plate se-
temperature of the materials, molds, apparatus, and the ambient
curely over the bar mold.
temperature of the mixing area shall be 73 °F 6 4 °F (23 °C 6
(3) Melting Chamber, of sufficient volume and heat capac-
2 °C), unless otherwise specified by the manufacturer. Record
ity to melt the sulfur mortar sample and maintain the tempera-
the actual temperature.
ture of the melt between 260 °F and 290 °F (127 °C and
6.3.2 Sulfur Mortars—The material shall be maintained at
143 °C).
275 °F 6 15 °F. The temperature of the molds and the ambient
(4) Laboratory Mixer, of such a type and speed to be
temperature of the mixing area shall be 73 °F 6 4 °F (23 °C 6
capable of lifting the aggregate without beating air into the
2 °C). Record the actual temperature.
melt.
6.3.3 For Sulfur Concrete, the material, mold, apparatus,
(5) Ladle, of sufficient capacity to completely pour one bar.
and mixing equipment shall be 275 °F 6 15 °F (135 °C 6
(6) Masking Tape, 1 in. (25 mm), or an equivalent.
8 °C), unless otherwise specified by the manufacturer. Refer to
5.3.2 Method B—Molds to permit the casting of bars 2 in. 6
Practice C1312.
⁄8 in. (50 mm 6 3 mm) square by 12 in. (300 mm) minimum
length. 6.4 Molding Test Specimens:
6.4.1 Lubricate the mold by applying a thin film of an
5.3.3 Method C—Molds to permit casting of rectangular
appropriate mold release or lubricant.
beams shall have a minimum cross-sectional dimension of 2 in.
and at least three times the nominal maximum size of the 6.4.2 Resin, Silicate, and Silica Materials—Mix a sufficient
coarse aggregate in the polymer concrete (Note 1). The bar
amount of the components in the proportions and in the manner
length shall be at least three times the beam depth plus 2 in. specified by the manufacturer of the materials. Fill the molds
one-half full. Remove any entrapped air by using a cutting and
NOTE 1—The nominal maximum size of coarse aggregate is that size
stabbing motion with a spatula or rounded-end rod. Fill the
next larger than the largest sieve on which at least 15 % of the coarse
remainder of the mold, working down into the previously
aggregate by weight is retained.
placed portion. Upon completion of the filling operation, the
5.4 Testing Machine—The testing machine shall be of any
tops of the specimens should extend slightly above the tops of
type sufficient to provide the required load and the rate of
the molds. When the molds have been filled, strike off the
deflection prescribed. It shall have been verified to have an
excess material, even with the top of the mold. Permit the
accuracy of 1.0 % or better within twelve months of the time of
material to remain in the mold until it has set sufficiently to
use in accordance with Practices E4. It shall be equipped with
allow removal without danger of deformation or breakage.
an appropriate device to record deflection and produce a graph
6.4.3 Silicate Materials—Some silicates may require cover-
of load versus deflection.
ing during the curing period. After removal from the molds,
acid-treat the specimens, if required, in accordance with the
5.5 Loading Nose and Supports—The loading nose and
recommendations given by the manufacturer. No other treat-
supports shall have cylindrical surfaces. To avoid excessive
ment shall be permitted. Record the method of treatment in the
indentation, the radius of the nose and supports shall be at least
1 1
report section under Conditioning Procedure.
⁄8 in. for Method A specimens, ⁄4 in. for Method B specimens,
and ⁄2 in. for Method C specimens. 6.4.4 Sulfur Mortars:
C580 − 18 (2023)
6.4.4.1 Assemble the mold described in 5.3.1 for the speci- where:
mens. Cover the bolt hole in the mold end piece with 1 in.
speed = the cross head speed, in./min (mm/min),
(25 mm) masking tape or other material.
L = span, in. (mm), and
d = depth of beam tested, in. (mm).
6.4.4.2 Carefully place the cover plate onto the mold,
covering only one of the end pieces. Apply a C-clamp around
8.3.2 For sulfur concrete, load the specimen continuously
the mold and cover plate in such a manner as to hold the
and without shock. The load may be applied rapidly up to
longitudinal mold pieces firmly in place with the cover plate.
approximately 50 % of the breaking load. Thereafter, apply the
6.4.4.3 Remove the uncovered end piece, being careful not
load at such a rate that constantly increases the extreme fiber
to disturb the side bars.
stress between 125 psi ⁄min and 175 psi ⁄min (0.86 MPa ⁄min
6.4.4.4 Stand the mold on end, supporting it in such a
and 1.21 MPa ⁄min), when calculated in accordance with 9.1,
manner that it will not tip.
until rupture occurs.
6.4.4.5 Slowly melt approximately 5 lb (2.3 kg) of sulfur
8.4 Place the specimen in the testing machine in such a
mortar in the melt chamber at a temperature of 275 °F 6 15 °F
manner that the faces of the beam that were in contact with the
while stirring gently with the laboratory mixer. (The mixer
true plane surfaces of the mold are in contact with the supports
speed should be controlled so that it is sufficient to lift the
and the center loading nose. Center the beam over the
aggregate without beating air into the melt.)
specimen supports.
6.4.4.6 Using the ladle, fill each mold completely, allowing
8.5 Apply the load to the specimen at the speed calculated in
the molten material to just reach the upper end of the mold.
8.3.1 (this is the cross head speed of the machine when running
6.4.4.7 Carefully watch the end of the fresh casting and
without load) and record load deflection data. Deflection shall
continually “top-off” the pour as shrinkage occurs (approxi-
be measured by either a transdu
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