ASTM_D_7857_-_16.pdf

Designation:D785716Standard Test Method forEvaluating the Flexural Properties and Internal BondStrength of Fire-Retarded Mat-Formed Wood StructuralComposite Panels Exposed to Elevated Temperatures1This standard is issued under the fixed designation D7857;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.1.Scope1.1 This test method is designed as a laboratory screeningtest.It is intended to establish an understanding of therespective contributions of the many wood material,fire-retardant,resin and processing variables,and their interactions,upon the mechanical properties of fire-retarded mat-formedwood structural composite(FRSC)panels as they affectflexural and internal bond(IB)performance and as they areoften affected later during exposure to high temperature andhumidity.Once the critical material and processing variableshave been identified through these small-specimen laboratoryscreening tests,additional testing and evaluation shall berequired to determine the effect of the treatment on the panelstructural properties and the effect of exposure to high tem-perature on the properties of commercially produced FRSCpanels.In this test method,treated structural composite panelsare exposed to a temperature of 77C(170F)and at least 50%relative humidity.1.2 The purpose of the preliminary laboratory-based testmethod is to compare the flexural properties and IB strength ofFRSC panels relative to untreated structural composite panelswith otherwise identical manufacturing parameters.The resultsof tests conducted in accordance with this test method providea reference point for estimating strength temperature relation-ships for preliminary purposes.They establish a starting pointfor subsequent full-scale testing of commercially producedFRSC panels.1.3 This test method does not cover testing and evaluationrequirements necessary for product certification and qualifica-tion or the establishment of design value adjustment factors forFRSC panels.NOTE1One potentially confounding limitation of this preliminaryscreening test method is that it may be conducted with laboratory panelsthat may not necessarily represent commercial quality panels.A finalqualification program should likely be conducted using commercialquality panels and the scope of the review should include evaluation of theeffects of the treatment and elevated temperature exposure on all relevantmechanical properties of the commercially produced panel.1.4 This test method is not intended for use with structuralplywood.1.5 The values stated in SI units are to be regarded asstandard.The values given in parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard.1.6 This standard 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.2.Referenced Documents2.1 ASTM Standards:2D9 Terminology Relating to Wood and Wood-Based Prod-uctsD198 Test Methods of Static Tests of Lumber in StructuralSizesD1037 Test Methods for Evaluating Properties of Wood-Base Fiber and Particle Panel MaterialsD1165 Nomenclature of Commercial Hardwoods and Soft-woodsD2395 Test Methods for Density and Specific Gravity(Rela-tive Density)of Wood and Wood-Based MaterialsD2915 Practice for Sampling and Data-Analysis for Struc-tural Wood and Wood-Based ProductsD3043 Test Methods for Structural Panels in FlexureD5516 Test Method for Evaluating the Flexural Properties ofFire-Retardant Treated Softwood Plywood Exposed toElevated TemperaturesD6305 Practice for Calculating Bending Strength DesignAdjustment Factors for Fire-Retardant-Treated PlywoodRoof Sheathing1This test method is under the jurisdiction of ASTM Committee D07 on Woodand is the direct responsibility of Subcommittee D07.07 on Fire Performance ofWood.Current edition approved March 1,2016.Published April 2016.DOI:10.1520/D785716.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 E84 Test Method for Surface Burning Characteristics ofBuilding MaterialsE176 Terminology of Fire StandardsE2768 Test Method for Extended Duration Surface BurningCharacteristics of Building Materials(30 min Tunnel Test)2.2 Other Standards:AWPA U-1 Commodity Specification H:Fire Retardants3NFPA 703 Standard for Fire Retardant Impregnated Woodand Fire Retardant Coatings for