ASTM_E_2431_-_12.pdf

Designation:E243112Standard Practice forDetermining the Resistance of Single Glazed AnnealedArchitectural Flat Glass to Thermal Loadings1This standard is issued under the fixed designation E2431;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 practice covers a procedure to determine theresistance of annealed architectural flat glass to thermallyinduced stresses caused by exposure to sun and shadows for aspecified probability of breakage(Pb).Proper use of thisprocedure is intended to reduce the possibility of thermalbreakage of annealed glass in buildings.1.2 This practice applies to vertical or sloped glazing inbuildings.1.3 This practice applies to monolithic and laminated glassof rectangular shape and assumes that all glass edges aresimply supported.1.4 This practice applies only to annealed flat soda-limesilica glass with clean cut,seamed,flat ground,or ground andpolished edges that are free from damage.The glass may beclear or tinted as well as coated(not including coatings thatreduce emissivity of the glass).1.5 This practice does not apply to any form of wired,patterned,etched,sandblasted,drilled,notched,or groovedglass or glass with surface and edge treatments,other thanthose described in 1.4,that alter the glass strength.1.6 This practice does not address uniform loads such aswind and snow loads,safety requirements,fire,or impactresistance.1.7 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.For conversion ofquantities in various systems of measurements to SI units referto IEEE/ASTM SI-10.1.8 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 Documents:2C162 Terminology of Glass and Glass ProductsE631 Terminology of Building ConstructionsIEEE/ASTM SI-10 Use of the International System of Units(SI)(the Modernized Metric System)2.2 Other Documents:32005 ASHRAE Handbook Fundamentals3.Terminology3.1 Definitions:3.1.1 For definitions of general terms related to buildingconstruction used in this test method refer to TerminologyE631,and for general terms related to glass and glass products,refer to Terminology C162.3.2 Definitions of Terms Specific to This Standard:3.2.1 edge bite,nthe width of the glass edge(measuredperpendicular to the cut edge,in the plane of the glass)that isprotected from direct exposure to solar irradiance by thewindow frame edge conditions expressed in mm(in.)seeTable 1.3.2.2 edge thermal stress factor(TSFedge),nthe ratio ofinduced thermal stress to the solar load,SL,as the result of theedge bite condition expressed in MPa/(W/m2).3.2.3 frame type,nthe manner in which the edges of theglass are supported in the window frame see Table 1.3.2.4 glass dimensions,nthe rectangular dimensions ofthe glass(not the daylight opening),with the width being thesmaller dimension and the length being the larger dimensionboth expressed in mm.1This practice is under the jurisdiction of ASTM Committee E06 on Perfor-mance of Buildings and is the direct responsibility of Subcommittee E06.51 onPerformance of Windows,Doors,Skylights and Curtain Walls.Current edition approved April 1,2012.Published May 2012.Originallyapproved in 2006.Last previous edition approved in 2011 as E2431 06(2011).DOI:10.1520/E2431-12.2For 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.3Available from American Society of Heating,Refrigerating,and Air-Conditioning Engineers,Inc.(ASHRAE),1791 Tullie Circle,NE,Atlanta,GA30329,http:/www.ashrae.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.5 incident solar irradiance(Insolation),(Is),namountof solar energy per unit time per unit area normal to glass,towhich the glass is exposed expressed in W/m2.3.2.6 probability of breakage(Pb),nthe number of litesper 1000 that would be predicted to break when exposed to thespecified thermal loading conditions.3.2.7 shadow thermal stress factor(TSFshadow),nthe ratioof induced thermal stress to the solar load,SL,as the result ofshadow condition expressed in MPa/(W/m2)(psi/Btu/hrft2).3.2.8 solar load(SL),nthe total amount of solar irradi-ance absorbed by the glass expressed in W/m2.TABLE 1 Frame TypesFrame TypeSketchInsulated edge-This c