ASTM D5574-94(2021)

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: D5574 − 94 (Reapproved 2021)
Standard Test Methods for
Establishing Allowable Mechanical Properties of Wood-
Bonding Adhesives for Design of Structural Joints
This standard is issued under the fixed designation D5574; 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 1.6.1 Ifthesubjectadhesiveswillbeusedtobondwoodthat
has been treated with a preservative, fire retardant, or any other
1.1 These test methods cover the principles for establishing
chemical to modify its properties, then the permanence of the
allowable mechanical properties for adhesives that can be used
adhesive shall be tested using wood adherends treated in the
todesignadhesive-bondedjointsforstructuralcomponentsand
same manner.
assemblies of wood or wood with other materials. These test
1.7 Factorsfordurability,permanence,andcreepderivedby
methods are modeled after Practice D245.
shear tests and analysis, are assumed to apply to tension
1.2 The properties determined are allowable shear stress,
(normal-to-the-bond) strength as well.
allowable tensile stress, and allowable shear modulus.
1.8 Requirements for production, inspection, and certifica-
1.3 In determination of allowable shear- and tensile-stress
tion of adhesives evaluated under these test methods are not
levels, these test methods are limited by the horizontal shear
included.
and tension perpendicular-to-the-grain capacity of the wood
1.9 The values stated in inch-pound units are to be regarded
adherends (hard maple, Acer saccharum, Marsh.). The adhe-
as standard. The values given in parentheses are mathematical
sives so tested may actually have shear or tensile allowable
conversions to SI units that are provided for information only
stresses exceeding the wood, but the determined allowable
and are not considered standard.
design stress levels are limited (upper bounded) by the wood in
these test methods. If a wood other than hard maple is used for 1.10 This international standard was developed in accor-
testing the adhesive, then the allowable strengths are upper
dance with internationally recognized principles on standard-
bounded by the properties of that particular wood. ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.4 The strength properties are determined by standard
mendations issued by the World Trade Organization Technical
ASTM test methods. As a result, only procedural variations
Barriers to Trade (TBT) Committee.
from the standards and special directions for applying the
results are given in these test methods.
2. Referenced Documents
1.5 Time-to-failure data derived from creep-rupture testing
2.1 ASTM Standards:
(see Test Method D4680) provide a measure of the ultimate
D245 Practice for Establishing Structural Grades and Re-
strength of an adhesive bond as a function of time at various
lated Allowable Properties for Visually Graded Lumber
levels of temperature and moisture.
D897 Test Method for Tensile Properties ofAdhesive Bonds
1.5.1 With proper caution, useful service life at a given
D905 Test Method for Strength Properties of Adhesive
shear stress level may be extrapolated from relatively short
Bonds in Shear by Compression Loading
loading periods.
D907 Terminology of Adhesives
D1101 Test Methods for Integrity of Adhesive Joints in
1.6 The resistance of the adhesive to permanent loss of
properties due to aging (permanence) is assessed by means of Structural Laminated Wood Products for Exterior Use
D1151 Practice for Effect of Moisture and Temperature on
strength tests after constant elevated-temperature and moisture
aging of test specimens. Adhesive Bonds
D2555 PracticeforEstablishingClearWoodStrengthValues
D2559 Specification for Adhesives for Bonded Structural
These test methods are under the jurisdiction of ASTM Committee D14 on
Adhesives and are the direct responsibility of Subcommittee D14.70 on Construc-
tion Adhesives. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved March 1, 2021. Published March 2021. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1994. Last previous edition approved in 2012 as D5574 – 94 (2012). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D5574-94R21. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5574 − 94 (2021)
Wood Products for Use Under Exterior Exposure Condi- 3.2 Definitions of Terms Specific to This Standard:
tions
3.2.1 allowable shear modulus, n—the modulus calculated
D2915 Practice for Sampling and Data-Analysis for Struc-
in accordance with Section 14, that is used for the design of a
tural Wood and Wood-Based Products
structural joint.
D3931 TestMethodforDeterminingStrengthofGap-Filling
3.2.2 basic shear modulus, n—the average shear modulus of
Adhesive Bonds in Shear by Compression Loading
30 specimens fabricated and tested in accordance with 13.1.
D3983 Test Method for Measuring Strength and Shear
3.2.3 basic shear strength, n—a near minimum value of the
Modulus of Nonrigid Adhesives by the Thick-Adherend
shear strength distribution determined as the one-sided lower
Tensile-Lap Specimen
confidence interval on the fifth percentile as determined in
D4027 Test Method for Measuring Shear Properties of
accordance with 7.1. (See lower 5 % tolerance limit.)
Structural Adhesives by the Modified-Rail Test
D4502 Test Method for Heat and Moisture Resistance of
3.2.4 basic tensile strength, n—anearminimumvalueofthe
Wood-Adhesive Joints
tensile strength distribution determined as the one-sided lower
D4680 Test Method for Creep and Time to Failure of
confidence interval on the fifth percentile as determined in
Adhesives in Static Shear by Compression Loading
accordance with 9.1. (See lower 5 % tolerance limit.)
(Wood-to-Wood)
3.2.5 creep factor, n—for modulus, the monotonic modulus
D4896 Guide for Use ofAdhesive-Bonded Single Lap-Joint
as a function of loading rate expressed as the decimal fraction
Specimen Test Results
of the basic modulus.
IEEE/ASTM SI 10 Standard for Use of the International
System of Units (SI): The Modern Metric System 3.2.6 creep factor, n—for strength, the estimated 30 year
creep rupture limit as a decimal fraction of the basic strength.
3. Terminology
3.2.7 delamination factor, n—a pass/fail factor based on the
percentage of delamination on the end grain of a laminate after
3.1 Definitions:
cyclic delamination treatment.
3.1.1 allowable design stress, n—a stress to which a mate-
3.2.7.1 Discussion—The factor is 0 or l: 0 if end-grain
rial can be subjected under stated service conditions with low
probability of mechanical failure within the design lifetime. delamination is greater than 10 % of total end-grain bondline;
1 if less than 10 % after cyclic soak-dry treatment.
(D4896)
3.1.1.1 Discussion—Allowable design stress is obtained by
3.2.8 durability factor, n—the average strength under el-
multiplying the basic stress by a safety factor and possibly one
evated test conditions expressed as a decimal fraction of the
or more modification factors as required by the intended
strength at standard condition.
service environment.
3.2.8.1 Discussion—Increases in temperature and moisture
3.1.2 allowable shear stress, n—in an adhesive-bonded
level usually lower strength temporarily, as long as the speci-
joint, the allowable design stress for structural joints subjected men is not so weakened that fracture occurs. Decreases in
to shear force.
temperature and moisture level usually increase strength.
Exceptions occur when increasing the temperature raises the
3.1.3 allowable tensile stress, n—in an adhesive-bonded
level of adhesive cure and strength, or decreasing the tempera-
joint, the allowable design stress for structural joints subjected
ture or moisture induces brittleness and stress concentrations.
to tension force.
3.2.9 lower 5 % nonparametric tolerance limit [NTL],
3.1.4 creep rupture, n—the fracture of a material resulting
n—an estimate of the one-sided lower confidence bond on the
from a sustained stress (or sum of stresses) above the creep
fifth percentile of the strength distribution determined as the
rupture limit.
lowest ranked value (fast order statistic) of sample of speci-
3.1.4.1 Discussion—The material may experience creep
mens from a population.
through the primary, secondary, and tertiary stages of rupture.
3.2.10 lower 5 % parametric tolerance limit [PTL], n—an
3.1.5 creep-rupture limit, n—the stress level below which
estimate of the lower confidence bound on the fifth percentile
creep rupture will not occur within a given time in a specified
of the strength distribution calculated as the mean of a sample
environment. See creep rupture.
minus the sample standard deviation multiplied by a confi-
3.1.6 durability, n—as related to adhesive joints, the endur-
dence level factor.
ance of joint strength relative to the required service condi-
3.2.11 lower 5 % tolerance limit, n— an estimate of the
tions. (D907)
one-sided lower confidence bound on the fifth percentile of the
3.1.6.1 Discussion—Service conditions may include water
strength distribution of a population of specimens.
and other chemicals, temperature, stress, radiation,
microorganisms, and other environmental factors.
3.2.12 modification factor, n—any external or internal factor
of the service environment that temporarily or permanently
3.1.7 permanence, n—the resistance of an adhesive bond to
alters the strength or stiffness of an adhesive.
deteriorating influences. (D907)
3.2.13 multiaxial stress, n—stress in two or three perpen-
3.1.8 structural adhesive, n—a bonding agent used for
dicular directions, bi- or triaxial stress.
transferring required loads between adherends exposed to
service environments typical for the structure involved. (D907) 3.2.13.1 Discussion—In most wood structures bonded with
D5574 − 94 (2021)
foragivenadhesiveforexteriorwet-useapplications.Ifthereisanydoubt
structural adhesives, multiaxial stress consists of a shear stress
that the adhesive will pass the delamination requirement, the user can
in the plane of, and tension stress normal to the plane of the
conduct this test before all others in order to save the expense of
adhesive layer.
conducting the other tests needlessly.
3.2.14 permanence factor, n—the estimated residual
strength at 30 years expressed as a decimal fraction of the
5. Significance and Use
original strength at standard conditions.
5.1 Safe and reliable mechanical properties for adhesives
3.2.14.1 Discussion—This factor accounts for permanent,
are necessary to achieve the full structural benefit of adhesives
usually long-term, changes in strength or modulus due to the
in bonded structural components and assemblies.
effects of factors such as heat, moisture, chemicals, ultraviolet
5.2 An adhesive’s properties exhibit a natural variation or
light, and biological agents.
distribution of values. The allowable design stress for an
3.2.15 safety factor, n—a reduction factor to account for
adhesive must be adjusted to allow for variability and environ-
uncertainty in establishing an allowable design stress.
mental effects to ensure human safety and prevent premature
3.2.15.1 Discussion—The safety factor accounts for pos-
failure of costly structures.
sible differences between laboratory and end-use conditions,
differences in adhesive production lots, bonding variables, and 5.3 Modification factors can be applied to the allowable
the assumption that there is no interaction between modifica- design stress by the design engineer as deemed appropriate for
tion factors. the expected service conditions of the adhesive, or in accor-
dance with the requirements of a building code.
4. Summary of Test Methods
5.4 The allowable properties developed under these meth-
4.1 These test methods are based on a conservative estimate
ods apply only to the actual adhesive formulation tested and
of the near minimum value of the distribution of adhesive
analyzed.
strengths measured by a standard test method. The basic
5.5 Theallowablepropertiesdevelopedforagivenadhesive
strength of the adhesive is the lower 5 % nonparametric
shall apply only to adhesive bondlines with thicknesses in the
tolerance limit obtained by a sample of 59 specimens. The
range for which data is available.
allowabledesignstressisthebasicstrengthreducedbyasafety
factor as a minimum:
6. Adhesive and Wood Preparation
allowable design stress 5 basic strength 3safety factor
6.1 Obtain a representative sample from each lot of adhe-
The allowable shear modulus is the mean modulus of a
sive to be tested.
group of specimens measured by a standard test method and
6.1.1 For liquid or paste adhesives, take a sample from each
adjusted by modification factors similar to those for strength as
lot of at least 1 qt (446 mL).
required by the service environment.
6.1.2 For adhesives consisting of more than one part, take a
sufficient sample of each part to prepare at least 2 lb (908 g) of
4.2 The allowable design stress (or modulus) can be modi-
adhesive at the time of test-specimen fabrication.
fied by one or more modification factors that are appropriate
6.1.3 For dry adhesives, take a sample from each lot
for the intended-service exposure of the adhesive.
weighing at least 1 kg (1.1 lb).
4.3 The modification factors used in these test methods are
durability, permanence, delamination, and creep. 6.2 Follow the adhesive manufacturer’s specifications for
4.3.1 Temperature and moisture are the principal variables proper packing, mixing, and handling of the sample.
of both the durability and permanence factors. Chemicals, such
6.3 Follow the adhesive manufacturer’s instructions for
as preservatives or fire retardants, may constitute a third
proper use of the adhesive. The information needed will vary
element of the durability and permanence factors. These
for different types of adhesive. Important information may
factors are shown in Appendix X1. Stress level and time, in
include:
addition to temperature and moisture, are important elements
6.3.1 The acceptable moisture-content range for the wood.
of the creep favor. Chemicals may be important to the creep
6.3.2 Complete mixing directions for the adhesive.
factoriftheyplasticizeorotherwisesoftentheadhesive.Cyclic
6.3.3 The acceptable range of conditions for adhesive
gradientsofmoistureandtemperatureareprincipalelementsof
application, such as rate of spread, thickness of wet film, bead
the delamination factor.
size, number of coats to be applied, minimum temperature for
4.3.2 Modification factors are derived from standard test
application, single or double spread, and conditions for drying
methods and specimens under critical-use conditions such as
where more than one coat is required.
extreme temperature, moisture, chemical, or stress levels
6.3.4 The acceptable range of open- and closed-assembly
expected in service.
time over the ambient temperature and humidity range speci-
4.4 Flow charts showing tests and calculations required to
fied.
establish allowable shear stress, allowable tensile stress per-
6.3.5 The acceptable range of curing conditions, including
pendicular to bond, and allowable shear modulus for a given
the pressure to be applied, if any; whether this pressure may be
adhesive are shown in Appendix X2.
provided by nails or staples, or both, or by other means; the
minimumtimeunderpressureandtheminimumtemperatureof
NOTE 1—The sequence described in the procedure sections of these test
methods are not absolute. The delamination factor sets a pass/fail criteria the assembly when under pressure. It should be stated whether
D5574 − 94 (2021)
this temperature is that of the bondline, or of the atmosphere in adhesives. Choose the standard test condition that equals, or
which the assembly is to be maintained. most closely approaches, the critical end-use conditions of the
adhesive application.
6.3.6 The acceptable storage conditions and storage time
prior to use. 7.2.3 Condition 30 specimens to equilibrium at each re-
quired temperature and moisture (critical end-use) condition.
6.4 Hard maple (Acer saccharum, Marsh.) is the standard
7.2.4 Determine the shear strength of specimens at equilib-
material for all test adherends. Other species may be selected
rium with the selected conditions, using either Test Method
by mutual consent of the parties requesting these tests. This
D905 or Test Method D3931.
could occur, for example, if it is thought that the wood species
7.2.5 Calculate the durability factor (C ) as the mean shear
d
mighthaveanadverseinteractionwiththeagingbehaviorofan
strength at the conditions of test, expressed as a percentage of
adhesive.Regardlessofthespeciesused,selectandpreparethe
¯
the mean shear strength (S) determined in accordance with
wood in accordance with the guidelines given in Test Method
7.1.5. Since only one durability factor can be operable at a
D905.
given time, use only the smallest durability factor of those
TEST METHOD FOR ALLOWABLE SHEAR STRESS determined in the subsequent calculation of the allowable
design stress.
7. Procedure
7.3 Determination of the Delamination Factor (C ):
del
NOTE 2—Refer to the testing and analysis path for determining
7.3.1 Fabricate three bonded assemblies, in accordance with
allowable shear stress in Appendix X2.
Sections 10 and 11 of Specification D2559, and cut three
7.1 Determination of the Basic Shear Strength (S ):
0.5
specimens from each assembly, as described in Section 13.
7.1.1 Fabricate 60 standard block-shear specimens repre-
7.3.2 Subject the specimens to the accelerated exposure in
senting at least twelve bonded assemblies. Use Test Method
accordance with Section 15 of Specification D2559.
D905 for bondlines less than ⁄32-in. (0.8 mm) thick, and Test
7.3.3 Evaluatethepercentageofdelaminationinaccordance
Method D3931 for bond lines exceeding this thickness.
with Section 15 of Specification D2559.
7.1.2 Assign 59 specimens to test. Save the extra specimen
7.3.4 Calculate delamination as the percentage of total
for a replacement.
end-grain bondline delaminated:
7.1.3 Condition the test specimens to equilibrium moisture
length of endgrain bondline that is delaminated/
content at 23°C (73.4°F) and 65 % relative humidity before
total length of endgrain bondline 3100
testing.
7.1.4 Test the specimens by the appropriate method (either
7.3.5 If delamination is less than 10 %, the delamination
Test Method D905 or Test Method D3931).
factor is 1. If delamination is greater than 10 %, or if more than
¯
7.1.5 Calculate the mean shear strength (S).
20 % of the total delamination (2 % actual) occurs within a
7.1.6 Determine the lower 5 % nonparametric tolerance single bondline, the delamination factor is 0.
limit [NTL] for shear strength.
7.4 Determination of the Creep Factor (C ):
c
7.1.7 The lower 5 % [NTL] is the basic shear strength
7.4.1 Fabricate ten block-shear specimens in accordance
(S ).
0.05
with Test Method D4680 for each intended test condition.
NOTE 3—A lower one-sided 95 % confidence bound on the fifth
7.4.2 Compare the lower 5 % tolerance limit value deter-
percentile of a strength distribution has the following property: if a series
mined for dry, bonded specimens (S ) determined in 7.1.6 to
0.5
of such confidence bounds are determined for a series of samples from the
thelower5 %tolerancelimitvaluesfordryandwetsolidwood
population, then 95 % of these confidence bo
...