ASTM D7565/D7565M-10(2017)
(Test Method)Standard Test Method for Determining Tensile Properties of Fiber Reinforced Polymer Matrix Composites Used for Strengthening of Civil Structures
Standard Test Method for Determining Tensile Properties of Fiber Reinforced Polymer Matrix Composites Used for Strengthening of Civil Structures
SIGNIFICANCE AND USE
5.1 This test method can be used to obtain the tensile force capacity and ultimate tensile strain of FRP material used for the strengthening of other structural materials such as, metals, timber, and reinforced concrete. The principal test variables could be the FRP constituents and fabrication method or the size or type of FRP laminate. The obtained tensile properties can be used for material specifications, quality control and assurance, structural design and analysis, and research and development.
5.2 This test method focuses on the FRP material itself, irrespective of the gripping method. Therefore, maximum force and strain data associated with failure or pullout at either grip are disregarded. The force capacity and maximum strain measurements are based solely on test specimens that fail in the gauge section.
SCOPE
1.1 This test method describes the requirements for sample preparation, tensile testing, and results calculation of flat fiber reinforced polymer (FRP) composite materials used for the strengthening of structures made of materials such as metals, timber, masonry, and reinforced concrete. The method may be used to determine the tensile properties of wet lay-up and pre-impregnated FRP composites fabricated on site or manufactured in a factory setting. The FRP composite may be of either unidirectional (0-degrees) or cross-ply (0/90 type) reinforcement. For cross-ply laminates, the construction may be achieved using multiple-layers of unidirectional fibers at either 0 or 90 degrees, or one or more layers of stitched or woven 0/90 fabrics. The composite material forms are limited to continuous fiber or discontinuous fiber-reinforced composites in which the laminate is balanced and symmetric with respect to the test direction. The method only covers the determination of the tensile properties of the FRP composite material. Other components used to attach the FRP material to the substrate, such as the primer, putty, and adhesive in externally bonded strengthening systems, are excluded from the sample preparation and testing detailed in this document. This test method refers to Test Method D3039/D3039M for conduct of the tests.
1.2 The values stated in either SI units or inch-pound units are to be regarded as standard. Within the text, the inch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance 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
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Standards Content (Sample)
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: D7565/D7565M − 10 (Reapproved 2017)
Standard Test Method for
Determining Tensile Properties of Fiber Reinforced Polymer
Matrix Composites Used for Strengthening of Civil
Structures
This standard is issued under the fixed designation D7565/D7565M; 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.
1. Scope 2. Referenced Documents
1.1 This test method describes the requirements for sample 2.1 ASTM Standards:
preparation, tensile testing, and results calculation of flat fiber D883 Terminology Relating to Plastics
reinforced polymer (FRP) composite materials used for the D3039/D3039M Test Method for Tensile Properties of Poly-
strengthening of structures made of materials such as metals, mer Matrix Composite Materials
timber, masonry, and reinforced concrete. The method may be D3878 Terminology for Composite Materials
used to determine the tensile properties of wet lay-up and D5229/D5229M TestMethodforMoistureAbsorptionProp-
pre-impregnated FRP composites fabricated on site or manu- erties and Equilibrium Conditioning of Polymer Matrix
factured in a factory setting. The FRP composite may be of Composite Materials
either unidirectional (0-degrees) or cross-ply (0/90 type) rein- D5687/D5687M Guide for Preparation of Flat Composite
forcement. For cross-ply laminates, the construction may be Panels with Processing Guidelines for Specimen Prepara-
achieved using multiple-layers of unidirectional fibers at either tion
0 or 90 degrees, or one or more layers of stitched or woven E6 Terminology Relating to Methods of Mechanical Testing
0/90 fabrics. The composite material forms are limited to E122 Practice for Calculating Sample Size to Estimate,With
continuous fiber or discontinuous fiber-reinforced composites Specified Precision, the Average for a Characteristic of a
in which the laminate is balanced and symmetric with respect Lot or Process
to the test direction. The method only covers the determination E177 Practice for Use of the Terms Precision and Bias in
of the tensile properties of the FRP composite material. Other ASTM Test Methods
components used to attach the FRP material to the substrate, E456 Terminology Relating to Quality and Statistics
such as the primer, putty, and adhesive in externally bonded
3. Terminology
strengthening systems, are excluded from the sample prepara-
tion and testing detailed in this document. This test method
3.1 Definitions—Terminology D3878 defines terms relating
refers to Test Method D3039/D3039M for conduct of the tests.
to high-modulus fibers and their composites. Terminology
D883definestermsrelatingtoplastics.TerminologyE6defines
1.2 The values stated in either SI units or inch-pound units
terms relating to mechanical testing. Terminology E456 and
are to be regarded as standard. Within the text, the inch-pound
E177 define terms relating to statistics. In the event of a
units are shown in brackets. The values stated in each system
conflict between terms, Terminology D3878 shall have prece-
are not exact equivalents; therefore, each system must be used
dence over the other standards.
independently of the other. Combining values from the two
systems may result in nonconformance with the standard.
3.2 Definitions of Terms Specific to This Standard:
1.3 This standard does not purport to address all of the 3.2.1 screed, v—to move a flat rule along the top of a
safety concerns, if any, associated with its use. It is the saturated laminate to level the top of the laminate and
responsibility of the user of this standard to establish appro- simultaneously remove excess resin.
priate safety and health practices and determine the applica-
3.2.2 shop-manufactured FRP composite, n—an FRP com-
bility of regulatory limitations prior to use.
positematerialmanufacturedundercontrolledconditionsusing
an automated process in a factory, typically with tight control
This test method is under the jurisdiction of ASTM Committee D30 on
Composite Materials and is the direct responsibility of Subcommittee D30.10 on
Composites for Civil Structures. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Jan. 1, 2017. Published January 2017. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2009. Last previous edition approved in 2010 as D7565/D7565M – 10. Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D7565_D7565M-10R17. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7565/D7565M − 10 (2017)
over the volume fractions and alignment of fibers, matrix, and strengthening of other structural materials such as, metals,
voids in the material as well as the cross-sectional geometry. timber, and reinforced concrete. The principal test variables
For strengthening applications, shop-manufactured FRP com- could be the FRP constituents and fabrication method or the
posites are typically bonded to the substrate subsequent to the size or type of FRP laminate. The obtained tensile properties
fabrication of the composite reinforcement. can be used for material specifications, quality control and
assurance, structural design and analysis, and research and
3.2.3 wet lay-up FRP composite, n—an FRP composite
development.
material fabricated by manually impregnating dry fibers with a
matrix of polymeric resin. Semi-automated processes such as
5.2 This test method focuses on the FRP material itself,
machine-aided wetting of fabrics before placement or vacuum-
irrespectiveofthegrippingmethod.Therefore,maximumforce
aidedimpregnationoflaminatesafterplacementareconsidered
and strain data associated with failure or pullout at either grip
part of wet lay-up FRP. For civil infrastructure strengthening
are disregarded. The force capacity and maximum strain
applications, the degree of control over the volume fractions of
measurementsarebasedsolelyontestspecimensthatfailinthe
fibers, matrix, and voids as well as the overall cross-sectional
gauge section.
geometry in wet lay-up FRP composites may be less than that
6. Interferences
for shop-manufactured composites on account of the manual
process. For strengthening applications, wet lay-up FRP com-
6.1 A summary of the interferences, specifically material
posites are typically applied to the substrate at the same time
and specimen preparation, gripping, system alignment, and
the dry fiber is impregnated.The impregnating resin acts as the
edge effects are presented in D3039/D3039M.
saturant for the FRP composite and as the bonding agent
6.2 Additional interferences may arise from lack of control
between the composite reinforcement and the substrate. Wet
in wet lay-up specimen preparation procedures outlined in
lay-up specimens may be fabricated in either a field or a
8.3.1. Specimen variations in resin content, ply thickness, void
laboratory setting.
content and degree of cure may contribute to variability in test
3.3 Symbols:
results.
3.3.1 CV—sample coefficient of variation.
*
7. Apparatus
3.3.2 F —force carrying capacity of FRP laminate per unit
width. 7.1 Requirements for testing machines and instrumentation
*
are the same as those given in D3039/D3039M, Section 7.
3.3.3 K —stiffness of FRP laminate per unit width.
3.3.4 L —extensometer gage length.
g 8. Sampling and Test Specimens
3.3.5 n—number of specimens.
8.1 Sampling—Test at least five specimens per test condi-
3.3.6 P—force carried by test coupon. tion unless valid results can be gained through the use of fewer
max
specimens, such as in the case of a designed experiment. For
3.3.7 P —maximum tensile force.
statistically significant data, the procedures outlined in Practice
3.3.8 s —sample standard deviation.
n−1
E122 should be consulted. Report the method of sampling.
3.3.9 w—coupon width.
NOTE 1—If specimens are to undergo environmental conditioning to
equilibrium, and are of such type or geometry that the weight change of
3.3.10 x—test result for an individual coupon from the
I
the material cannot be properly measured by weighing the specimen itself
sample population for a given property.
(suchasatabbedmechanicalcoupon),thenuseanothertravelercouponof
the size (but without tabs) to determine when equilibrium has been
3.3.11 x¯—mean or average (estimate of mean) of a sample
reached for the specimens being conditioned.
population for a given property.
8.2 Geometry—Variation in specimen width should be no
3.3.12 σ—normal stress.
greater than 61%. Specimens width should be determined per
Test Method D3039/D3039M, Section 7.1. Other dimensions
4. Summary of Test Method
shall conform to Test Method D3039/D3039M Section 8.2.1
4.1 Flat FRP specimens are prepared using a wet lay-up
with the exception of thickness, which is not required to be
fabrication procedure or cut from a shop-manufactured lami-
measured. Specimen thickness may however be measured as
nate.Fortestingpurposes,wetlay-upmaterialmaybeprepared
partofthegeneralcharacterizationofthespecimen,andshould
in a laboratory or field setting, as the testing objectives dictate.
be reported if measured.
The testing of the specimens is carried out according to the
provisions ofTest Method D3039/D3039M.The ultimate force NOTE 2—Calculations according to this method are based on force per
unit coupon width and stiffness per unit coupon width. Specimen
perunitwidthofthematerialisdeterminedfromthemaximum
thickness is not required for these calculations.
force carried before failure. If the load-strain response of the
8.2.1 Specimen Width—Minimum specimen width for uni-
material is monitored with strain gages or extensometers, then
directional shop-manufactured and wet lay-up FRP specimens
the stiffness of the material per unit width and the ultimate
shall be 25 mm [1.0 in.]. Minimum width for cross-ply
tensile strain of the material may be determined.
specimens shall be 25 mm [1.0 in.] for shop-manufactured
5. Significance and Use
composites and 38 mm [1.5 in.] for wet lay-up composites.
5.1 This test method can be used to obtain the tensile force
NOTE 3—For both unidirectional and cross-ply laminates, where fibers
capacityandultimatetensilestrainofFRPmaterialusedforthe are used in large bundles (i.e, rovings, tows) that will be wider than 3 mm
D7565/D7565M − 10 (2017)
[0.12 in.] when laid into the laminate, it is recommended that a specimen
diamond tooling has been found to be extremely effective for
width of 38 mm [1.5 in.] or higher be used.
many material systems. Edges should be flat and parallel
within the tolerances specified in 8.2. See Appendix X3 of
8.3 Specimen Preparation:
Guide D5687/D5687M for specific recommendations on speci-
8.3.1 Wet Lay-up FRP—A polymer release film, typically
men machining methods.
600 x 600 mm [24 x 24 in.] is placed on a smooth, flat
8.3.4 Labeling—Label the specimens so that they will be
horizontal surface. The release film should be at least 0.076
distinct from each other and traceable back to the raw material.
mm [0.003 in.] thick and made of a polymer that will not
adhere to the resin used to impregnate the fibers. Usually, Labeling must be unaffected by the test and must not affect the
outcome of the test.
acetate and nylon are acceptable. Resin is first applied to the
release film. The first ply of dry fiber preform with a minimum
9. Calibration
dimension of 300 x 300 mm [12 x 12 in.] is saturated or coated
with the specified amount of resin and placed on the release 9.1 The accuracy of all measuring equipment shall have
film. This can be done using a properly calibrated saturator certified calibrations that are current at the time of use of the
machineorusingamanufacturer-specifiedfibertoresinweight equipment.
ratio.Thespecifiednumberofpliesatthespecifiedangles(0or
10. Conditioning
90 degrees) are sequentially impregnated with resin and
stacked onto the release film using the specified amount of 10.1 The recommended pre-test condition is effective mois-
resinperplyperunitareaasintheactualinstallation.Usingthe ture equilibrium at a specific relative humidity as established
flat edge of a small hand tool or a grooved roller, air bubbles byTest Method D5229/D5229M; however, if the test requestor
are worked out of the material. The bubbles should be worked doesnotexplicitlyspecifyapre-testconditioningenvironment,
out in the direction of the primary fibers to ensure that no no conditioning is required and the specimens may be tested as
damage is caused to the fibers. A second release film is then prepared.
placed over the material to provide protection. An alternative
10.2 The pre-test specimen conditioning process, to include
methodtoeliminateairbubblesistousetheflatedgeofasmall
specified environmental exposure levels and resulting moisture
paddle on the outer side of the upper release film to force the
content, shall be reported with the test data.
entrapped air out of the material with a screeding action in the
10.3 If no explicit conditioning process is performed the
primary fiber direction. In order to ensure a smooth top surface
specimen conditioning process shall be reported as “uncondi-
of the FRP material, a rigid flat plate should be placed on top
tioned” and the moisture content as “unknown.”
of the top layer of release film while the resin cures. The
NOTE 6—The term moisture, as used in Test Method D5229/D5229M,
laminate should be placed in an area of the jobsite so as to not
includes not only the vapor of a liquid and its condensate, but the liquid
interfere with the installation and allowed to cure according to
itself in large quantities, as for immersion.
the manufacturer’s recommendation.After the specified curing
11. Procedure
procedure is complete, the release films are removed from the
panel. Specimens may be cut and tabbed after the curing
11.1 Follow procedures detailed in Test Method D3039/
procedure.
D3039M Section 11 for testing the specimens. Record the
max
maximum failure load P . If the stiffness of the specimen is
NOTE 4—The final fiber, resin, and void content of the material will
to be calculated, record the load-strain relationship and the
depend on the method of rolling or screeding the material during
fabrication. If the aim of testing is to evaluate FRPmaterial representative
strain at failure during the test.
of the installed strengthening material, rolling and scre
...
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