ASTM_D_2915_-_10.pdf

Designation:D291510Standard Practice forSampling and Data-Analysis for Structural Wood and Wood-Based Products1This standard is issued under the fixed designation D2915;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONSampling and data analysis should be integrated in the design and evaluation of wood andwood-based structural products.This practice is useful in assessing the appropriateness of the assignedproperties and for checking the effectiveness of grading procedures.Statistical methodologies areprovided to serve as a basis for the empirical establishment and evaluation of mean and near minimumproperty estimates.These population estimates are then used by product standards to assign structuraldesign values for use with an established design methodology(that is,allowable stress design,loadand resistance factor design,limit states design,etc.).Near-minimum property estimates are typicallyused by the product standards to define the performance for a variety of structural properties wherestrength is a primary consideration(that is,extreme fiber stress in bending,axial tension,axialcompression,shear,and elasticity for buckling concerns).Population mean estimates are often usedto assess serviceability design criteria where strength is not the primary design concern(that is,elasticity estimates used for deformation calculations,permissible compression stress at adeformation,etc.).For situations where a manufactured product is sampled repeatedly or lot sizes are small,alternativetest methods as described in Ref(1)2may be more applicable.1.Scope1.1 This practice covers sampling and analysis proceduresfor the investigation of specified populations of wood andwood-based structural products referred to in this standard asproducts.Appropriate product standards should be referencedfor presentation requirements for data.Depending on theinterest of the user,the population from which samples aretaken may range from the products produced at a specificmanufacturing site to all the products produced in a particulargrade from a particular geographic area,during some specifiedinterval of time.This practice generally assumes that thepopulation is sufficiently large so that,for sampling purposes,it may be considered infinite.Where this assumption isinadequate,that is,the population is assumed finite,many ofthe provisions of this practice may be employed but thesampling and analysis procedure must be designed to reflect afinite population.The statistical techniques embodied in thispractice provide procedures to summarize data so that logicaljudgments can be made.This practice does not specify theaction to be taken after the results have been analyzed.Theaction to be taken depends on the particular requirements of theuser of the product.1.2 The values stated in inch-pound units are to be regardedas the standard.1.3 This practice does not purport to address the adjustmentfactors needed to adjust test data to standardized mechanicaland environmental conditions(that is,temperature,moisture,test span,or load duration).Additionally,it provides a basis forstatistical estimates that will typically require further adjust-ment to determine design values for use with an accepteddesign methodology(that is,allowable stress,limit states,orload and resistance factor design).It shall be the responsibilityof the user to seek out the appropriate adjustments in specificproduct standards.1.4 This practice does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1This practice is under the jurisdiction of ASTM Committee D07 on Wood andis the direct responsibility of Subcommittee D07.02 on Lumber and EngineeredWood Products.Current edition approved Nov.1,2010.Published January 2011.Originallyapproved in 1970 as D2915 70 T.Last previous edition approved in 2003 asD2915 03.DOI:10.1520/D2915-10.2The boldface numbers in parentheses refer to the list of references at the end ofthis practice.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 2.Referenced Documents2.1 ASTM Standards:3D9 Terminology Relating to Wood and Wood-Based Prod-uctsD198 Test Methods of Static Tests of Lumber in StructuralSizesD245 Practice for Establishing Structural Grades and Re-lated Allowable Properties for Visually Graded LumberD1990 Practice for Establishing Allowable Properties forVisually-Graded Dimension Lumber from In-Grade Testsof Full-Size SpecimensD2555 Practice for Establishing Clear Wood Strength ValuesD3737 Practice for Establishing Allowable Properties