Significance and Use
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.
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 D 3737, but provides an alternative method for establishing characteristic values. Lay-up combinations developed in accordance with Practice D 3737 are not required to be governed by this standard.
Note 1—The models described by Practice D 3737 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/AITC A190.1 or CSA O122.
1.5 Adjustments to characteristic values to determine reference values for design shall be in accordance with Practice D 2915 for allowable stress design (ASD) or Specification D 5457 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 D 3737. 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.
1.7 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.
1.8 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.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
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 Properties for Structural Glued Laminated Timber (Glulam)
D4761 Test Methods for Mechanical Properties of Lumber and Wood-Base Structural Material
D5456 Specification for Evaluation of Structural Composite Lumber Products
D5457 Specification for Computing Reference Resistance of Wood-Based Materials and Structural Connections for Load and Resistance Factor Design
D6815 Specification for Evaluation of Duration of Load and Creep Effects of Wood and Wood-Based Products
PS-20 Voluntary Product Standard, ALS Available from National Institute of Standards and Technology (NIST), 100 Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov.
bending; characteristic value; flexural; flexure; full-scale; glulam; laminated; lay-up; modulus; timber; Flexural testing; Full-scale testing; Glued laminated timber (glulam); Timber ;
ICS Number Code 79.060.99 (Other wood-based panels)
ASTM International is a member of CrossRef.
Citing ASTM Standards
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