ASTM D7341-21

Standard Practice for Establishing Characteristic Values for Flexural Properties of Structural Glued Laminated Timber by Full-Scale Testing

SIGNIFICANCE AND USE
10.1 Full-scale bending testing is an effective way to determine flexural properties of structural glued laminated timber (glulam) beams. However, testing of large glulam members is cost prohibitive. Mathematical models, when confirmed by full-scale test results, are useful tools to assign flexural properties for glulam. This practice provides guidelines for sampling and testing full-scale glulam beams to determine their flexural properties and to validate mathematical models intended for use in assigning flexural design values.
SCOPE
1.1 This practice describes procedures for full scale testing of structural glued laminated timber (glulam) to determine or verify characteristic values used to calculate flexural design properties. Guidelines are given for: (1) testing individual structural glued laminated timber lay-ups (with no modeling), (2) testing individual glulam combinations (with limited modeling), and (3) validating models used to predict characteristic values.  
1.2 This practice is limited to procedures for establishing flexural properties (Modulus of Rupture, MOR, and Modulus of Elasticity, MOE). Some of the principles for sampling and analysis presented may be applicable to other properties. However, other properties may require additional testing considerations that are beyond the scope of this practice.  
1.3 This practice is not intended to supersede the provisions of Practice D3737, but provides an alternative method for establishing characteristic values. Lay-up combinations developed in accordance with Practice D3737 are not required to be governed by this standard.
Note 1: The models described by Practice D3737 have been developed and modified based on more than 50 years of experience and many test programs. In some cases, however, it may be desirable to develop a new model based on other input properties or using lumber materials or grades not covered by that standard.  
1.4 Details of production, inspection, and certification are beyond the scope of this document. However, for test results to be representative of production, quality control systems shall be in place to ensure consistent quality. Manufacturing shall conform to recognized manufacturing standards such as ANSI A190.1 or CSA O122.  
1.5 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.  
1.6 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 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.

General Information

• Status: Published
• Publication Date: 31-Mar-2021
• ICS: 79.060.99 - Other wood-based panels
• Technical Committee: D07 - Wood
• Drafting Committee: D07.02 - Lumber and Engineered Wood Products

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: D7341 − 21
Standard Practice for
Establishing Characteristic Values for Flexural Properties of
1
Structural Glued Laminated Timber by Full-Scale Testing
This standard is issued under the fixed designation D7341; 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 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 This practice describes procedures for full scale testing
responsibility of the user of this standard to establish appro-
of structural glued laminated timber (glulam) to determine or
priate safety, health, and environmental practices and deter-
verify characteristic values used to calculate flexural design
mine the applicability of regulatory limitations prior to use.
properties. Guidelines are given for: (1) testing individual
1.7 This international standard was developed in accor-
structural glued laminated timber lay-ups (with no modeling),
dance with internationally recognized principles on standard-
(2) testing individual glulam combinations (with limited
ization established in the Decision on Principles for the
modeling), and (3) validating models used to predict charac-
teristic values. Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
1.2 This practice is limited to procedures for establishing
Barriers to Trade (TBT) Committee.
flexural properties (Modulus of Rupture, MOR, and Modulus
of Elasticity, MOE). Some of the principles for sampling and
2. Referenced Documents
analysis presented may be applicable to other properties.
2
However, other properties may require additional testing con-
2.1 ASTM Standards:
siderations that are beyond the scope of this practice.
D198 Test Methods of Static Tests of Lumber in Structural
Sizes
1.3 This practice is not intended to supersede the provisions
D245 Practice for Establishing Structural Grades and Re-
of Practice D3737, but provides an alternative method for
lated Allowable Properties for Visually Graded Lumber
establishing characteristic values. Lay-up combinations devel-
D2915 Practice for Sampling and Data-Analysis for Struc-
oped in accordance with Practice D3737 are not required to be
governed by this standard. tural Wood and Wood-Based Products
D3737 Practice for Establishing Allowable Properties for
NOTE 1—The models described by Practice D3737 have been devel-
oped and modified based on more than 50 years of experience and many
Structural Glued Laminated Timber (Glulam)
test programs. In some cases, however, it may be desirable to develop a
D4761 Test Methods for Mechanical Properties of Lumber
new model based on other input properties or using lumber materials or
and Wood-Based Structural Materials
grades not covered by that standard.
D5456 Specification for Evaluation of Structural Composite
1.4 Details of production, inspection, and certification are
Lumber Products
beyond the scope of this document. However, for test results to
D6815 Specification for Evaluation of Duration of Load and
be representative of production, quality control systems shall
Creep Effects of Wood and Wood-Based Products
be in place to ensure consistent quality. Manufacturing shall
2.2 Other Standards:
conform to recognized manufacturing standards such as ANSI
3
AITC Test T119 Full Size End Joint Tension Test
A190.1 or CSA O122.
ANSI A190.1 American National Standard for Wood Prod-
1.5 The values stated in inch-pound units are to be regarded
4
ucts – Structural Glued Laminated Timber
as standard. No other units of measurement are included in this
standard.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
1
This practice is under the jurisdiction of ASTM Committee D07 on Wood and Standards volume information, refer to the standard’s Document Summary page on
is the direct responsibility of Subcommittee D07.02 on Lumber and Engineered the ASTM website.
3
Wood Products. Available from the Pacific Lumber Inspection Bureau, 1010 South 336th St.
Current edition approved April 1, 2021. Published April 2021. Originally #210 Federal Way, WA 98003, http://www.aitc-glulam.org.
4
approved in 2008. Last previous edition approved in 2014 as D7341 – 14. DOI: Available from APA—The Engineered Wood Association, 7011 South 19th
10.1520/D7341-21. Street, Tacoma, WA 98466, http:/
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7341 − 14 D7341 − 21
Standard Practice for
Establishing Characteristic Values for Flexural Properties of
1
Structural Glued Laminated Timber by Full-Scale Testing
This standard is issued under the fixed designation D7341; 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
1.1 This practice describes procedures for full scale testing of structural glued laminated timber (glulam) to determine or verify
characteristic values used to calculate flexural design properties. Guidelines are given for: (1) testing individual structural glued
laminated timber lay-ups (with no modeling), (2) testing individual glulam combinations (with limited modeling), and (3)
validating models used to predict characteristic values.
1.2 This practice is limited to procedures for establishing flexural properties (Modulus of Rupture, MOR, and Modulus of
Elasticity, MOE). Some of the principles for sampling and analysis presented may be applicable to other properties. However, other
properties may require additional testing considerations that are beyond the scope of this practice.
1.3 This practice is not intended to supersede the provisions of Practice D3737, but provides an alternative method for establishing
characteristic values. Lay-up combinations developed in accordance with Practice D3737 are not required to be governed by this
standard.
NOTE 1—The models described by Practice D3737 have been developed and modified based on more than 50 years of experience and many test programs.
In some cases, however, it may be desirable to develop a new model based on other input properties or using lumber materials or grades not covered
by that standard.
1.4 Details of production, inspection, and certification are beyond the scope of this document. However, for test results to be
representative of production, quality control systems shall be in place to ensure consistent quality. Manufacturing shall conform
to recognized manufacturing standards such as ANSI A190.1 or CSA O122.
1.5 Adjustments to characteristic values to determine reference values for design shall be in accordance with Practice D2915 for
allowable stress design (ASD) or Specification D5457 for load and resistance factor design (LRFD).
1.6 Adjustments to ASD reference values for end-use conditions intended for design purposes shall be performed in accordance
with Practice D3737. The same adjustment factors shall apply to LRFD reference values, except that the ASD load duration factor
shall be replaced by an appropriate LRFD time effect factor as determined in accordance with recognized industry practice.
1.5 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this
standard.
1
This practice is under the jurisdiction of ASTM Committee D07 on Wood and is the direct responsibility of Subcommittee D07.02 on Lumber and Engineered Wood
Products.
Current edition approved Feb. 1, 2014April 1, 2021. Published March 2014April 2021. Originally approved in 2008. Last previous edition approved in 20092014 as
D7341 – 09.D7341 – 14. DOI: 10.1520/D7341-14.10.1520/D7341-21.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D7341 − 21
1.6 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.7 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D198 Test Methods of Static Tests of Lumber in Structural Sizes
D245 Practice for Establishing Structural Grades and Related Allowable Properties for Visually Graded Lumber
D2915 Practice for Sampling and Data-Analysis for Structural Wood and Wood-Based Products
D3737 Practice for Establishing Allowable Proper
...