1. Scope

1.1 Due to the number of specimens involved and the number of mechanical properties to be evaluated, a methodology for evaluating the data and assigning allowable properties to both tested and untested grade/size cells is necessary. Sampling and analysis of tested cells are covered in Practice D 2915. The mechanical test methods are covered in Test Methods D 198 and D 4761. This practice covers the necessary procedures for assigning allowable stress and modulus of elasticity values to dimension lumber from In-Grade tests. The practice includes methods to permit assignment of allowable stress and modulus of elasticity values to untested sizes and grades, as well as some untested properties.

1.2 A basic assumption of the procedures used in this practice is that the samples selected and tested are representative of the entire global population being evaluated. This approach is consistent with the historical clear wood methodology of assigning an allowable property to visually-graded lumber which was representative of the entire growth range of a species or species group. Every effort shall be made to ensure the representativeness of the test sample.

1.3 This practice covers the principles and procedures for establishing allowable stress values for bending, tension parallel to grain, compression parallel to grain and modulus of elasticity values for structural design from 'In-Grade' tests of full-size visually graded solid sawn dimension lumber. This practice is focused on, but is not limited to, grades which used the concepts incorporated in Practice D 245 and were developed and interpreted under American Softwood Lumber PS 20-70.

Note 1In the implementation of the North American In-Grade test program, allowable stress values for compression perpendicular to grain and shear parallel to grain for structural design were calculated using the procedures of Practice D 245.

1.4 This practice only covers dimension lumber.

1.5 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.

ASTM Standards

D9 Terminology Relating to Wood and Wood-Based Products

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

D1165 Nomenclature of Commercial Hardwoods and Softwoods

D2555 Practice for Establishing Clear Wood Strength Values

D2915 Practice for Sampling and Data-Analysis for Structural Wood and Wood-Based Products

D4442 Test Methods for Direct Moisture Content Measurement of Wood and Wood-Base Materials

D4444 Test Method for Laboratory Standardization and Calibration of Hand-Held Moisture Meters

D4761 Test Methods for Mechanical Properties of Lumber and Wood-Base Structural Material

IEEE/ASTM SI 10 Standard for Use of the International System of Units (SI): The Modern Metric System

American Softwood Lumber Standard

Keywords

visually-graded; dimension lumber; allowable stress; modulus of elasticity; In-Grade;

ICS Code

ICS Number Code 79.040 (Wood, sawlogs and sawn timber)

DOI: 10.1520/D1990-00R02E01

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