ASTM_E_2461_-_12.pdf

Designation:E246112Standard Practice forDetermining the Thickness of Glass in Airport TrafficControl Tower Cabs1This standard is issued under the fixed designation E2461;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 the determination of the thicknessof glass installed in airport traffic control towers(ATCT)toresist a specified design loading with a selected probability ofbreakage less than or equal to either 1 lite per 1000 or 4 litesper 1000 at the first occurrence of the design wind loading.1.2 The procedures apply to common outward sloping cabglass designs for which the specified loads do not exceed 10kPa(210 psf).1.3 The procedures assume control tower cab glass has anaspect ratio no greater than 2.1.4 The procedures assume control tower cab glass has anarea no less than 1.86 square metres(20 square feet).1.5 The procedures apply only to annealed monolithic,annealed laminated,or annealed insulating glass having arectangular or trapezoidal shape.1.6 The use of the procedures assumes the following:1.6.1 Annealed monolithic and annealed laminated glassinstalled in ATCTs shall have continuous lateral support alongtwo parallel edges,along any three edges,or along all fouredges;1.6.2 Insulating glass shall have continuous lateral supportalong all four edges;and1.6.3 Supported glass edges are simply supported and freeto slip in plane.1.7 The procedures do not apply to any form of wired,patterned,etched,sandblasted,or glass types with surfacetreatments that reduce the glass strength.1.8 The procedures do not apply to any form of heat treatedglass,chemically strengthened glass,or any type of glass withsurface treatments intended to increase the glass strength.1.9 The procedures address the determination of thicknessand construction type to resist a specified design wind load ata selected probability of breakage.The final glass thicknessand construction determined also depends upon a variety ofother factors(see 5.3).1.10 These procedures do not address blast loading on glass.1.11 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.1.12 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 to determine theapplicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C162 Terminology of Glass and Glass ProductsC1036 Specification for Flat GlassE631 Terminology of Building ConstructionsE1300 Practice for Determining Load Resistance of Glass inBuildings2.2 American Society of Civil Engineers Standard:3ASCE 7 Minimum Design Loads for Buildings and OtherStructures3.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 E1300.3.2 Definitions of Terms Specific to This Standard:3.2.1 annealed(AN)glass,na flat,monolithic,glass lite ofuniform thickness;it is formed by a process whereby themagnitudes of the residual stresses are nearly zero.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 2005.Last previous edition in 2011 as E2421 05(2011).DOI:10.1520/E2461-12.2For 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 Civil Engineers(ASCE),1801 AlexanderBell Dr.,Reston,VA 20191,http:/www.asce.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.2 aspect ratio(AR),nthe ratio of the long dimensionto the short dimension for rectangular glass or the ratio of thelong dimension to the short dimension of the rectangle thatcompletely encloses trapezoidal glass.In these procedures,ARis always equal to or greater than 1.0.NOTE1The rectangle that completely encloses the trapezoid has twosides parallel to the horizontal edges of the trapezoid and the other twosides perpendicular to the horizontal edges of the trapezoid.All dimen-sions shall be measured from edge to edge of glass.3.2.3 equivalent rectangular area(ERA),nthe product ofthe longest hori