ASTM D7617/D7617M-11

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D7617/D7617M − 11
Standard Test Method for
Transverse Shear Strength of Fiber-reinforced Polymer
Matrix Composite Bars
This standard is issued under the fixed designation D7617/D7617M; 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 E4 Practices for Force Verification of Testing Machines
E6 Terminology Relating to Methods of Mechanical Testing
1.1 This test method specifies the test requirements for
E122 Practice for Calculating Sample Size to Estimate,With
(FRP) composite smooth round rods and textured bars for
Specified Precision, the Average for a Characteristic of a
determining the transverse shear strength via a double shear
Lot or Process
fixture. FRP rods and bars are often loaded in transverse shear
E456 Terminology Relating to Quality and Statistics
whentheseelementsareusedasdowelsinconcretepavements,
as stirrups in concrete beams, or as shear reinforcements in
3. Terminology
glued-laminated wood beams, for example.
3.1 Terminology in D3878 defines terms relating to high-
1.2 The values stated in either SI units or inch-pound units
modulus fibers and their composites. Terminology in D883
are to be regarded separately as standard. The values stated in
defines terms relating to plastics. Terminology in E6 defines
each system may not be exact equivalents; therefore, each
terms relating to mechanical testing. Terminology in E456
system shall be used independently of the other. Combining
defines terms relating to statistics and the selection of sample
values from the two systems may result in non-conformance
sizes. In the event of a conflict between terms, Terminology in
with the standard.
D3878 shall have precedence over the other terminology
1.2.1 Within the text, the inch-pound units are shown in
standards.
brackets.
3.2 Definitions of Terms Specific to This Standard:
1.3 This standard does not purport to address all of the
3.2.1 bar, n—a linear element, with a substantially round
safety concerns, if any, associated with its use. It is the
cross section, often with surface undulations or a coating of
responsibility of the user of this standard to establish appro-
particles that promote mechanical interlock with concrete.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
3.2.2 double shear fixture, n—atestfixturethatresultsinthe
desired shear force being applied to two distinct sections of the
2. Referenced Documents
specimen.
2.1 ASTM Standards:
3.2.3 failure, n—cleavage of the bar under test into three
A615/A615M SpecificationforDeformedandPlainCarbon-
pieces or into two pieces where the second non-cleaved shear
Steel Bars for Concrete Reinforcement
plane is highly damaged.
D883 Terminology Relating to Plastics
3.2.4 nominal cross sectional area, n—a measure of cross
D3878 Terminology for Composite Materials
sectional area of a bar, determined over at least one represen-
D5229/D5229M TestMethodforMoistureAbsorptionProp-
tative length, used to calculate stress.
erties and Equilibrium Conditioning of Polymer Matrix
3.2.5 projected outer diameter, n—the smallest diameter of
Composite Materials
a circle through which a bar, with its undulations or coatings,
D7205/D7205M Test Method for Tensile Properties of Fiber
will pass. The bar may touch the circle but must pass through
Reinforced Polymer Matrix Composite Bars
without undue force.
3.2.6 rod, n—a bar with a smooth circular cross section and
This test method is under the jurisdiction of ASTM Committee D30 on
no texture or deformations.
Composite Materials and is the direct responsibility of Subcommittee D30.10 on
Composites for Civil Structures.
3.2.7 standard cross sectional area, n—the cross sectional
Current edition approved March 1, 2011. Published May 2011. DOI: 10.1520/
area of a standard numbered steel concrete reinforcing bar as
D7617_D7617M-11.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
given in A615/A615M, Table 1.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
3.2.8 surface undulation, n—variation in the area,
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. orientation, or shape of cross section of a bar along its length,
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7617/D7617M − 11
intended to enhance mechanical interlock between a bar and 5.2 Experience with this test method and the accompanying
concrete, made by any of a number of processes such as, for fixture is primarily with smooth rods and textured bars with
example, indentation, addition of extra materials, and twisting. diameters ranging from 6 mm to 25 mm [0.25 in. to 1 in.]. The
method may be used for rods or bars of larger diameters, but
3.3 Symbols:
the overall geometry of the test fixture may need to be
3.3.1 A—nominalorstandardcrosssectionalareaofarodor
increased.
bar, see D7205/D7205M.
3.3.2 P —maximum shear force carried by specimen N
S
6. Interferences
[lbf].
6.1 Blade Alignment—The two lower and one upper blade
3.3.3 τ —transverse shear strength, MPa [psi].
u
used for shearing the specimen are machined to fit the
projectedouterdiameterofthebar.Theslotwidthanddiameter
4. Summary of Test Method
of the blades should be selected so that the bar fits snugly into
4.1 Alength of fiber-reinforced polymer (FRP) rod or bar is
the fixture, but does not bind. The test results may be sensitive
fittedintoadoubleshearfixturewithappropriatecuttingblades
to the slot width for bars which have significant texture or
and clamped into place. The shear fixture is mounted into a
deformations. See Fig. 1.
universal mechanical testing machine and monotonically
6.2 Surface Texture—The method has been used with tex-
loaded to failure while recording force and crosshead displace-
tured bars with surface roughness amplitudes of up to 6 5%
ment.
variation in diameter relative to the average bar diameter as
5. Significance and Use measured with a dial caliper. Use on bars with greater variation
in surface roughness or regions with substantially-reduced
5.1 This test method for transverse shear strength is in-
cross-sections may lead to increased scatter in test results or
tended for use in laboratory tests in which the principal
failure of the specimens away from the two shearing planes.
variable is the size or type of FRP bars. The test may be used
for smooth round rods or on bars with a textured or undulating 6.3 Measurement of Cross Sectional Area—The nominal
surface added to promote bond of the bars to Portland cement cross sectional area of textured or undulating bars is measured
concrete. This test method establishes values of transverse by immersing a prescribed length of the specimen in water to
shear strength for material specifications, quality control, determine its buoyant weight, as described in D7205/D7205M.
quality assurance, research and development, and may also be Bar configurations that trap air during immersion (aside from
used for structural design purposes. minor porosity) cannot be assessed using this method. This
NOTE 1—The blades should fit snugly around the bar without binding.
FIG. 1 Potential Interference for Undulating or Textured Bar
D7617/D7617M − 11
method may not be appropriate for bars that have large as shown in Figs. 2 and 3. Thin shim stock (suggested
variations in cross sectional area along the length of the bar. thickness of 0.08 mm [0.003 in.]) may be placed between the
bar seats and the guides to ensure a close running fit of the
6.4 Clamping Force—The bar should be firmly clamped to
upper blade between the two lower blades (see Fig. 5a and b
the bar seats before testing.Testing without sufficient clamping
and Fig. 6a and b). The upper blade is loose, and is fit onto the
will lead to lower apparent transverse shear strength results.
bar prior to testing.
Experience with the fixture and small-diameter glass-
reinforced FRProds has shown that two set screws on one end NOTE 1—Other versions of this test fixture have been developed that
combine the two lower bar seats into one unified component with a fixed
of the bar and one set screw on the other end is sufficient for
gap of 50 mm [2.0 in.] between the bar seats to allow for insertion of the
this clamping.
lower blades. These fixtures are acceptable for use with this standard but
the fit between the lower and upper blades is not adjustable.
6.5 System Alignment—The test is typically completed on
universal testing machine with compression platens. Care
7.2 Dimensional Tolerances—Dimensional tolerances for
should be taken that bottom compression platen is completely
the components of the test fixture produced in U.S. customary
flat and large enough for entire surface of test fixture to bear,
units shall be standard tolerances as follows: Unless noted
and is perpendicular to the axis of loading.
otherwise on the drawings, dimensions given to one decimal
place (0.X in.) shall be 60.05 in., dimensions given to two
7. Apparatus
decimal places (0.0X in.) shall be 60.01 in., and dimensions
7.1 The test fixture consists of two bar seats, two lower given to three decimal places (0.00X in.) shall be 60.005 in.
blades, and two guides machined from steel. These parts are
For components produced in SI units, standard tolerances for
bolted together with two threaded rods with washers and nuts dimensions given to zero decimal places (X mm) shall be 60.1
FIG. 2 Transverse Shear Fixture Assembled (Side Views and Axonometric View)
D7617/D7617M − 11
NOTE 1—(1) Assembled fixture with sheared specimen and (2) main body of fixture disassembled (note presence of shim stock on guides).
FIG. 3 Photographs of Test Fixture
mm, dimensions given to one decimal place (0.X mm) shall be established so that the diameter of the semi-circle is tangent
60.25 mm, dimension given to two decimal places (0.0X mm) with the angled side of the bar seat (see Fig. 1 and Fig. 5).
shall be 60.10 mm.
7.4.2 Upper Blade—The upper blade is machined from 25
mm [1.000 in.] thick steel having a precision ground finish of
7.3 Bar Seats—The two bar seats are identical and have a
0.80 µm [32 µin.] or better. The upper blade has the same
v-shaped bed for supporting the ends of the bars (see Fig. 4a
machined slot and diameter as the two lower blades (see Fig.
and b).
7a and b).
7.4 Blades—The lower blades and upper blade should be
NOTE2—Thisstandarddoesnotgivespecificdimensionalrequirements
machined from tool steel, hardened to 55 to 58 HRC.
for the slots and diameters of the lower and upper blades, as a wide range
7.4.1 Lower Blades—The two lower blades are machined
of textured bars and smooth rods, produced under both SI and US
from 12 mm [0.500 in.] thick steel having a precision ground
Customary standards, may be tested using this method. Fig. 5 and Fig. 7
finish of 0.80 µm [32 µin.] or better. The slots in the lower
depict the dimensions of lower and upper blades for a 3/8 in. and a 10 mm
blades are machined based on the diameter of the bars to be smooth rod. In U.S. practice, blades for the apparatus are typically made
for smooth and textured rods in diameters that range between 6 mm (0.25
tested. For smooth round rods, the width of the slot shall be
in.) to 25 mm (1 in.).
0.10 mm [0.004 in.] wider than the measured diameter of the
rods. For textured or undulating bars the slot shall be equal to 7.5 Guides—The guides are machined from the same steel
the projected outer diameter from the roughly circular bar. The as the upper blade.The two guides are of equal thickness to the
depth of the semi-circle at the bottom of the slot shall be upper blade and may be tapered to facilitate insertion of the
D7617/D7617M − 11
FIG. 4 a Bar Seat (U.S. Customary Units)
upper blade into the fixture. The holes in the guides align with velocity of the movable head shall be capable of being
the holes in the lower blades and in the bar seats so that the regulated as specified in 11.4.
entire assembly can be bolted together (see Fig. 6a and b). 7.7.3 Force Indicator—The testing machine force-sensing
device shall be capable of indicating the total force being
7.6 Strap—Straps, nominally 12 mm [0.5 in.] thick, and
carried by the test specimen. This device shall be essentially
mounted at the top of both bar seats, are used to clamp the bar
free from inertia lag at the specified rate of testing and shall
or rod firmly into the bar seats during testing. Socket-head cap
indicate the force with an accuracy over the force range(s) of
screws pass through threads in the straps and clamp the
interest of within 6 1 % of the indicated value. The force
specimens onto the bar seats. (see Fig. 8a and b).
range(s) of interest may be fairly low for modulus evaluation,
7.7 Testing Machine—The testing machine shall be in con-
much higher for strength evaluation, or both, as required.
formance with Practices E4 and shall satisfy the following
requirements:
8. Sampling and Test Specimens
7.7.1 Testing Machine Heads—The testing machine shall
8.1 Specimens shall be representative of the lot or batch
have both an essentially stationary head and a movable head.
being tested. In the test section of the specimen, no postpro-
The movable head shall be equipped with a deflection measur-
duction machining, abrading, or other such processing is
ing device.
permitted.
7.7.2 Drive Mechanism—The testing machine drive mecha-
nism shall be capable of imparting to the movable head a 8.2 Sampling—Test at least five specimens per test condi-
controlled velocity with respect to the stationary head. The tion unless valid results can be gained through the use of fewer
D7617/D7617M − 11
FIG. 4 b Bar Seat (SI Units) (continued)
specimens, such as in the case of a designed experiment. For 10. Conditioning
statistically significant data, the procedures outlined in E122
10.1 The recommended pre-test condition is effective mois-
shouldbeconsulted.Themethodofsamplingshallbereported.
ture equilibrium at a specific relative humidity as established
8.3 The length of the specimen shall be 225 mm [9 in.].
byTest Method D5229/D5229M; however, if the test requestor
doesnotexplicitlyspecifyapre-testconditioningenvironment,
8.4 The cross sectional area of textured or undulating bars
no conditioning is required and the specimens may be test
...