ASTM D5055-00a

Designation: D 5055 – 00a
Standard Specification for
Establishing and Monitoring Structural Capacities of
Prefabricated Wood I-Joists
This standard is issued under the fixed designation D5055; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope E380 Practice for Use of the International System of Units
(SI) (The Modernized Metric System)
1.1 General—This specification gives procedures for estab-
E529 Guide for Conducting Flexural Tests on Beams and
lishing, monitoring, and reevaluating structural capacities of
Girders for Building Construction
prefabricated wood I-joists. Capacities considered are shear,
E699 Practice for Criteria for Evaluation of Agencies
moment, and stiffness. Procedures for establishing common
Involved in Testing, Quality Assurance, and Evaluating
details are given and certain design considerations specific to
Building Components in Accordance With Test Methods
wood I-joists are itemized.
Promulgated By ASTM Committee E-6
1.2 Contents of the Standard—An index and brief descrip-
2.2 Other Standards:
tion of the main features of this specification are given in
U.S. Product Standard PS-1 Construction and Industrial
X1.1.1.
Plywood
1.3 Development of the Standard—The development and
U.S. Product Standard PS-2 Performance Standard for
intent of this specification is discussed in Appendix X1.
Wood-Based Structural-Use Panels
1.4 This standard does not purport to address all of the
CSA O112.7 Resorcinol and Phenol-Resorcinal Resin Ad-
safety concerns, if any, associated with its use. It is the
hesives
responsibility of the user of this standard to establish appro-
CSA O151 Canadian Softwood Plywood
priate safety and health practices and determine the applica-
CSA O325.0 Construction Sheathing
bility of regulatory limitations prior to use. Aspecific precau-
CSA O452 Design Rated OSB
tionary statement is given in 6.1.1.5.
Lumber Grading Rules Approved by American Lumber
2. Referenced Documents Standards Committee (ALSC) or Canadian Lumber Stan-
dards Accreditation Board (CLSAB)
2.1 ASTM Standards:
D198 TestMethodsofStaticTestsofLumbersinStructural
3. Terminology
Sizes
3.1 Definition:
D245 Practice for Establishing Structural Grades and Re-
3.1.1 prefabricated wood I-joist—a structural member
lated Allowable Properties for Visually Graded Lumber
manufactured using sawn or structural composite lumber
D2559 Specification for Adhesives for Structural Lami-
flanges and structural panel webs, bonded together with exte-
nated Wood Products for Use Under Exterior (Wet Use)
3 rior exposure adhesives, forming an “I” cross-sectional shape.
Exposure Conditions
These members are primarily used as joists in floor and roof
D2915 Practices for Evaluating Allowable Properties for
2 construction.
Grades of Structural Lumber
3.2 Definitions of Terms Specific to This Standard:
D4761 Test Methods for Mechanical Properties of Lumber
and Wood-Base Structural Material
E4 Practices for Force Verification of Testing Machines
Annual Book of ASTM Standards, Vol 14.02.
Annual Book of ASTM Standards, Vol 04.07.
1 7
This specification is under the jurisdiction of ASTM Committee D7 on Wood Available from APA The Engineered Wood Association, P.O. Box 11700,
andisthedirectresponsibilityofSubcommitteeD07.02onLumberandEngineered Tacoma, WA 98411and PFS Research Foundation, 2402 Daniels Street, Madison,
Wood Products. WI 53718.
Current edition approved Oct. 10, 2000. Published December 2000. Originally AvailablefromCanadianStandardsAssociation,178RexdaleBlvd.,Etobicoke,
published as D5055–90. Last previous edition D5055–00. Ontario, Canada M9W 1R3.
2 9
Annual Book of ASTM Standards, Vol 04.10. Available fromAmerican Lumber Standard Committee (ALSC), P.O. Box 210,
Annual Book of ASTM Standards, Vol 15.06. Germantown, MD 20874. Canadian Lumber Standards Accreditation Board
Annual Book of ASTM Standards, Vol 03.01. (CLSAB), 1055 W. Hastings St., Vancouver, B.C., Canada V6E 2E9.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 5055
3.2.1 capacity (or structural capacity)—the numeric result addition, all panels shall meet the equivalent of Exposure I
of certain calculations specified in this specification. requirements as specified in PS-1 or PS-2.
3.2.2 design value—the numeric value claimed by the
5.3 Adhesives—Adhesives used to fabricate components as
manufacturer as appropriate for use in structural analysis.
well as the finished products shall conform to the requirements
inSpecificationD2559(CSAO112.7inCanada)foruseunder
NOTE 1—A brief discussion of this issue is found in X1.9.
exterior (wet-use) exposure conditions. Appendix X3 gives
3.2.3 structural composite lumber—a composite of wood
additional information and standards that shall be considered
elements (for example, wood strands, strips, veneer sheets, or
when qualifying adhesives and adhesive-bonded materials.
acombinationthereof),bondedwithanexteriorgradeadhesive
and intended for structural use in dry service conditions.
6. Qualification
6.1 General—This section describes procedures, both em-
4. Design Considerations
pirical and analytic, for initial qualification of the structural
4.1 Design Value Adjustments:
capacities of prefabricated wood I-joists. Qualification is re-
4.1.1 Duration of Load—Prefabricated wood I-joists shall
quired for certain common details of I-joist application since
be designed using the strength adjustment for load duration
they often influence structural capacities. All capacities are to
used in sawn lumber. This adjustment is determined in accor-
be reported with three significant digits. Any time significant
dance with the section on Duration of Load Under Modifica-
changesinjoistorapplicationdetails,manufacturingprocesses
tion ofAllowable Properties for Design Use in Practice D245.
ormaterialspecificationsoccur,qualificationisrequired,asfor
4.1.2 Repetitive Members—Prefabricated wood I-joists are
a new manufacturer or product line.
permitted to have the following moment capacity adjustment
6.1.1 Testing—Qualification tests shall be conducted or
increasesforrepetitivememberusedependinguponthetypeof
witnessed by a qualified agency as defined in 8.1. All test
flange material:
results are to be certified by the qualified agency.
Visually graded solid-sawn lumber 15 %
6.1.1.1 Sample Size—Thenumberofspecimensspecifiedin
Machine stress-rated lumber 7 %
6.2, 6.3, 6.4, and 6.5 are minimums. The producer wishing to
Structural composite lumber 4 %
evaluatethevalidityofthesamplesizewillfindaprocedurein
4.1.2.1 Toqualifyfortheincrease,thewoodI-joistsmustbe
4.7 of Practice D2915.
partofawood-framingsystemconsistingofatleastthreewood
6.1.1.2 Test Specimens—Materials and fabrication proce-
I-joists joined by transverse load distributing elements ad-
dures of test specimens shall be as typical of intended
equate to support the design load. The wood I-joists shall not
production as can be obtained at the time of manufacturing
be spaced more than 24 in. on center.
qualification specimens.
4.1.3 Treatments—Some pressure treatments affect material
NOTE 2—It is desirable to conduct preliminary tests to aid the selection
strength and the quality of prefabricated wood I-joists.Treated
of representative specimens.
I-joists shall not be used without evaluation of such effects.
4.1.4 Environment—The capacities developed in this speci-
6.1.1.3 Test Accuracy—Tests in accordance with this speci-
fication are applicable to joists used under dry conditions such
fication are to be conducted in a machine or apparatus
asinmostcoveredstructures.Appropriateadjustmentsforuses
calibrated in accordance with Practices E4 except that the
in other environments shall be made.
percentage error shall not exceed 62.0.
4.2 Shear Design:
6.1.1.4 Test Methods—Methods generally applicable to the
4.2.1 Neglecting loads within a distance from the support
full-section joist tests required herein are Methods E529, with
equal to the depth of the member shall not be permitted.
the following exceptions: (a) the methods are applicable to
4.2.2 Adjustmentstothesheardesignvaluenearthesupport
bothqualificationandqualitycontroland;(b)loadrateshallbe
or at locations of continuity or where reinforcements are
as specified in the following sections, and (c) delays between
provided must be substantiated by independent testing to the
load increments are not required. Required tension and com-
general intended criteria for shear capacity herein.
pression tests shall be substantially in accordance with Meth-
4.3 Volume Effects—Abrief discussion of volume effects in
ods D198 orTest Methods D4761 with load rates as specified
I-joists is given in Appendix X2.
in the following sections. All test report formats and content
shall be in keeping with the intended use of the results and be
5. Materials
agreed upon by all involved parties prior to the test.
6.1.1.5 Test Safety—All full-scale structural tests are poten-
5.1 Flange Stock:
tially hazardous and appropriate safety precautions must be
5.1.1 All flange material shall conform to the requirements
observedatalltimes.Oneparticularconcernisthepotentialfor
of 6.3.
lateral buckling during full-section I-joist tests and appropriate
5.1.2 End joints in purchased flange stock are permitted
lateral restraint must be maintained at all times.
provided such joints conform to the general intent and Section
6.2 Shear Capacity Qualification:
10 of this specification.
5.2 Web Material—Panels shall conform to manufacturing 6.2.1 Initial capacity shall be established from either test
orperformancestandardsrecognizedbytheapplicablegovern- results or calculations. The equations used for the calculation
ing code. Examples are U.S. Product Standard PS-1 or CSA method shall be confirmed by a test program; the details of
O151, and U.S. Product Standard PS-2 or CSA O325.0. In which are beyond the scope of this specification. Explanations
D 5055
of the statistics used in the analysis of test results, with an 6.2.12 The mean ultimate shear values shall show logical
example, are given in Appendix X4. progression of strength as a function of depth. A linear
regression analysis of the mean values shall have a coefficient
6.2.2 Factors which influence shear capacity include web
of determination (r ) of at least 0.9, or the specified tests of
type, thickness, and grade; web to flange joint; joint type in
6.2.3 must be repeated. If the second test set fails to meet the
web (machined, butted, glued or not, reinforced, etc.). Each
criteria, all depths which have been skipped must also be
combination of these web factors must be tested separately in
tested. (A check of the regression criteria is given in X4.4.5.)
accordance with 6.2.3, unless the critical combination in a
6.2.12.1 Data from joist depths where failure is web buck-
proposed grouping is first established by test. Flange stiffness
ling shall be excluded from the regression analysis, if: (a)
influencesshearstrength:ifarangeofflangesizesistobeused
including the results causes failure to meet the criteria of
with a given combination of web factors, all sizes must be
6.2.12; or (b) the producer determines the reduction in regres-
tested unless all values are to be based on tests with the
sionlineslopeisunacceptable.Ineithercase,alldepthsgreater
smallest flange. When a range of species or grades of either
than the shallowest excluded, shall be tested.
sawn or composite lumber is to be grouped, preliminary tests
shall be conducted to determine which is critical. Joists with
NOTE 3—Depending on joist details and material, there will be some
structural composite lumber flanges, such as LVL, must be
depth where web buckling appears as a mode of failure. Further increases
tested separately from joists with sawn lumber flanges.
indepthwillresultinconsistentwebbuckling,andatsomepointultimate
strength will reduce compared to shallower joists.
6.2.3 For each web factor combination, a minimum of ten
specimens shall be tested for each critical joist depth. Critical
6.2.12.2 Whennomorethanthreedepthsaretobequalified,
joist depths are minimum and maximum product depths with
the correlation is not necessary, but each depth must be tested.
approximate 4-in. (102-mm) depth increments between. If the
6.2.13 The shear capacity of the product shall be limited to
installation of specific reinforcement as defined in the manu-
that calculated by taking into account sample size, test result
facturer’s literature is required at a certain depth to maintain
variability, and reduction factors. Data from tests at different
product performance in the progression of a series of depths
joist depths included in regression analysis are permitted to be
within a combination, the product must be tested at this depth
combined to obtain a pooled estimate of variability.
plus the adjacent depth which does not require specific
6.2.13.1 Combining Data—The regression equation from
reinforcement.
6.2.12providestheexpectedmeanshearstrength(P )fordepth
e
6.2.4 Specimen length shall be that which usually produces
(d):
i
failures in shear. The bearing length shall be adequate to
P 5 A 1 Bd (1)
e i
usually produce shear failure instead of a bearing failure but
shallnotexceed4in.(102mm),unlessjustified.Thereshallbe where A and B are intercept and slope of the equation.
a minimum horizontal distance of 1 ⁄2 times the joist depth 6.2.13.2 Where too few depths are involved for correlation
between the face of the support and the edge of the load pad.
in 6.2.12, when the tests fail the regression criteria, or where
depths are excluded from the correlation, no combining is
6.2.5 On one end of the specimen, a vertical web joint, if
allowed and each such depth shall be evaluated separately.
used, shall be located approximately 12 in. (305 mm) from the
6.2.13.3 The mean and standard deviation of the data from
face of the support or ⁄2 the distance between the support and
¯
the load pad. each depth tested are ( P) and (S).The coefficient of variation
i i
is:
6.2.6 The load shall be applied to the top flange either as a
single point load at center span or as two point loads of equal ¯
v 5 S/P (2)
i i i
distance from the center span. Load pads shall be of sufficient
Let n be the number of tests for each depth (d) tested and
i i
length to prevent local failure.
included in the regression analysis. Then the coefficient of
6.2.7 The load shall be applied at a uniform rate so that
variation in the combined data sets is:
anticipated failure will occur in not less than 1 min.
( n 21! v
@~ #
6.2.8 Any required web reinforcements developed in 6.6.1 i i
v 5 (3)
Œ
(n 2 J
i
shall be installed a
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