1、Designation: E2461 12 (Reapproved 2017)Standard 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 re
2、vision, 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 contr
3、ol 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 l
4、oads 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 lamina
5、ted, 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 f
6、ouredges;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 redu
7、ce 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 specif
8、ied 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 valu
9、es 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 stand
10、ard to establish appro-priate safety and health practices and to determine theapplicability of regulatory limitations prior to use.1.13 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles fo
11、r theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C162 Terminology of Glass and Glass ProductsC1036 Specification for Flat GlassE631 Terminology of Buil
12、ding 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 use
13、d in this practice refer to Terminology E631,1This practice is under the jurisdiction of ASTM Committee E06 on Perfor-mance of Buildings and is the direct responsibility of Subcommittee E06.52 onGlass Use in Buildings.Current edition approved April 1, 2017. Published April 2017. Originallyapproved i
14、n 2005. Last previous edition in 2012 as E2461-12. DOI: 10.1520/E2461-12R17.2For 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 onth
15、e 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 StatesThis international standard was developed in accord
16、ance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1and for general terms related to
17、glass and glass products, referto Terminology C162.3.2 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.3.2.2 aspect ratio (AR), nthe
18、 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.NOTE 1The rectangle that completely encloses the
19、 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 horizontal glass d
20、imension and the length of theedge perpendicular to the horizontal dimension in the plane ofthe glass. All dimensions shall be measured from edge to edgeof glass.3.2.4 designated thickness for laminated glass (LG), nthedesignated thickness for LG as Table 1 specifies.3.2.5 designated thickness for m
21、onolithic glass, nthe des-ignated or nominal thickness commonly used in specifying aparticular glass product, based on the minimum thicknessespresented in Table 2 and Specification C1036.3.2.6 glass breakage, nthe fracture of any lite or ply inmonolithic, laminated, or insulating glass resulting fro
22、m stressthat an applied uniform lateral load induces.3.2.7 insulating glass (IG) unit, nconsists of any combi-nation of two glass lites, as defined herein, that enclose a sealedspace filled with air or other gas.3.2.8 laminated glass (LG), na flat-lite of uniform thick-ness that is fabricated by bon
23、ding two or more monolithic glasslites or plies of equal thickness, as defined herein, together withpolyvinyl butyral (PVB) interlayer(s).3.2.9 lateral, adjperpendicular to the glass surface.3.2.10 load, na uniformly distributed lateral pressure.3.2.10.1 design load, nthe magnitude of the 3-seconddu
24、ration load used to design glass for ATCT cabs. Equationsused herein for computing magnitudes for design loads adjustglass self weight to a magnitude consistent with a 3-secondduration.3.2.10.2 specified design load, nthe magnitude in kPa(psf), type (for example, wind or self-weight) and duration of
25、the load. The wind load has a duration of approximately3 seconds. Glass self-weight (Table 2) has a long duration,typically equal to the in-service life of the window glass lite.Earth facing cab glass is only subjected to wind load and itsself-weight.3.2.10.3 long duration load, nany load lasting ap
26、proxi-mately 30 days or longer.3.2.10.4 short duration load, nany load lasting approxi-mately 3 seconds, such as, wind load.TABLE 1 Thickness Designations for Laminated GlassLaminated glassdesignation, t,mm (in.)Laminated glass constructionnominal thickness, mm (in.)glass/PVB/glassLaminated glass th
27、icknessdesignation for use in theseprocedures mm (in.)6(14)2.7/0.76/2.7 (lami)/0.030/(lami)6(14)3/0.76/3 (18)/0.030/(18)3/1.52/3 (18 )/0.060/(18)8(516) 4/0.76/4 (532 )/0.030/(532) 8 (516)10 (38) 5/0.76/5 (316)/0.030/(316) 10 (38 )11 (716) 5/1.52/5 (316 )/0.060/(316)12 (12) 6/0.76/6 (14)/0.030/(14) 1
28、2 (12 )13 (916) 6/1.52/6 (14 )/0.060/(14)16 (58)8/0.76/8 (516)/0.030/(516)16 (58)8/1.52/8 (516)/0.060/(516)8/2.28/8 (516 )/0.090/(516)19 (34)10/0.76/10 (38)/0.030/(38)19 (34)10/1.52/10 (38)/0.060/(38)10/2.28/10 (38 )/0.090/(38)25 (1)12/1.52/12 (12)/0.060/(12)25 (1)12/2.28/12 (12 )/0.090/(12)32 (114)
29、16/1.52/16 (58)/0.060/(58)32 (114)16/2.28/16 (58 )/0.090/(58)38 (112 )19/1.52/19 (34)/0.060/(34)38 (112 )19/2.28/19 (34)/0.090/(34)TABLE 2 Thickness Designations, Minimum Glass Thickness,and Unit Self-WeightNominal thickness ordesignation, mm (in.)Minimum thickness,mm (in.)Glass weightPa (psf)2.7 (l
30、ami) 2.59 (0.102) 67.0 (1.40)3.0 (18) 2.92 (0.115) 74.2 (1.55)4.0 (532) 3.78 (0.149) 99.1 (2.07)5.0 (316) 4.57 (0.180) 124 (2.59)6.0 (14) 5.56 (0.219) 149 (3.11)8.0 (516) 7.42 (0.292) 199 (4.15)10.0 (38) 9.02 (0.355) 248 (5.18)12.0 (12) 11.91 (0.469) 298 (6.22)16.0 (58) 15.09 (0.595) 397 (8.29)19.0
31、(34) 18.26 (0.719) 472 (9.85)22.0 (78) 21.44 (0.844) 546 (11.4)25.0 (1)* 24.4 (0.969) 622 (13.0)32 (1 14)A27.38 (1.22) 795 (16.6)38 (1 12)A31.6 (1.47) 943 (19.7)ANot a glazing industry standard thickness designation.E2461 12 (2017)23.2.11 minimum thickness of monolithic glass, nthe mini-mum allowabl
32、e thickness associated with a nominal or desig-nated glass thickness as given in Table 2 and SpecificationC1036.3.2.12 probability of breakage (Pb), nthe theoretical frac-tion of glass lites or plies that would break at the firstoccurrence of the resistance load, typically expressed in litesper thou
33、sand.4. Summary of Practice4.1 The use of these procedures requires a specified designload that shall consist of the wind load and the factored lateralcomponent of glass weight. The total design load shall notexceed 10 kPa (210 psf).4.2 The procedures specified herein facilitate determinationof the
34、thickness of an annealed window glass constructionrequired to resist the specified design loading for the selectedprobability of breakage.4.3 This standard procedure uses methods in Practice E1300to determine the approximate lateral deflection of the geomet-ric center of the window glass constructio
35、n. Annex A2 pro-vides deflection charts for laminated glass thicknesses largerthan those contained in Practice E1300.5. Significance and Use5.1 This standard procedure facilitates determination of thethickness of a glass construction required to resist a specifieddesign load with a selected probabil
36、ity of breakage.5.2 This standard procedure addresses the following glassconstructions: annealed monolithic, annealed laminated, andinsulating glass fabricated with annealed monolithic or an-nealed laminated glass, or both.5.3 Use of these procedures assume:5.3.1 The glass is free of edge damage and
37、 is properlyglazed,5.3.2 The glass has not been subjected to abuse,5.3.3 The surface condition of the glass is typical of glassthat has been in service for several years, and is significantlyweaker than freshly manufactured glass due to minor abrasionson exposed surfaces,5.3.4 The glass edge support
38、 system is sufficiently stiff tolimit the lateral deflections of the supported glass edges to lessthan1175 of their lengths. The specified design load shall beused for this calculation, and5.3.5 The center of glass deflection shall not result in loss ofedge support. Typically maintaining center of g
39、lass deflectionat or below the magnitude of three times the nominal glassthickness assures that no loss of edge support will occur.5.4 Many other factors affect the selection of glass type andthickness. These factors include but are not limited to: thermalstresses, the effects of windborne debris, e
40、xcessive deflections,behavior of glass fragments after breakage, seismic effects,heat flow, edge bite, noise abatement, potential post-breakageconsequences, and so forth. In addition, considerations setforth in federal, state, and local building codes along withcriteria presented in safety glazing s
41、tandards and site specificconcerns may control the ultimate glass type and thicknessselection.6. Procedure6.1 Select a probability of breakage, glass type orconstruction, and glass thickness(es).6.2 Compute the design load for monolithic or singlelaminated glass according to:LD5 LW12LGcos (1)where:L
42、D= denotes the design load,LW= denotes the wind load,LG= denotes the weight of the glass, and = denotes the acute angle the glass makes with thehorizontal. For monolithic or single laminated glazing,the user shall obtain LGfrom Table 2 for the nominalglass thickness. For insulating glass, LGshall co
43、nsist ofthe weights of both glass lites as determined fromTable 2.6.3 Monolithic Single Glazing Continuously SupportedAlong all Four Edges:6.3.1 Determine the ERA.6.3.2 Determine the AR.6.3.3 Determine the required glass thickness from Fig. A1.1(PB= 0.001) or Fig.A1.2 PB= 0.004) for the design load,
44、 ERA,and AR.6.3.4 Determine the approximate maximum center of glassdeflection using procedures from Practice E1300.6.4 Single Laminated Glazing Continuously SupportedAlong all Four Edges:6.4.1 Determine the ERA.6.4.2 Determine the AR.6.4.3 Determine the required glass thickness from Fig. A1.3(PB= 0.
45、001) or Fig. A1.4 (PB= 0.004) for the design load,ERA, and AR.6.4.4 Determine the approximate maximum center of glassdeflection using procedures from Practice E1300.6.5 Monolithic Single Glazing Simply Supported Continu-ously Along Two Opposite Sides or any Three Sides:6.5.1 Determine the Unsupporte
46、d Glass Length.6.5.2 Determine the required glass thickness from Fig. A1.5(PB= 0.001) or Fig. A1.6 (PB= 0.004) for the design load,ERA, and AR.6.5.3 Determine the approximate maximum center of glassdeflection using procedures from Practice E1300.6.6 Single Laminated Glazing Simply Supported Continu-
47、ously Along Two Opposite Sides or any Three Sides:6.6.1 Determine the unsupported glass length.6.6.2 Determine the required glass thickness from Fig. A1.7(PB= 0.001) or Fig. A1.8 (PB= 0.004) for the design load,ERA, and AR.6.6.3 Determine the approximate maximum center of glassdeflection using proce
48、dures from Practice E1300.6.7 Insulating Glass (IG) with Monolithic Glass Lites ofEqual (Symmetric) Glass Type and Thickness.E2461 12 (2017)36.7.1 Compute the design load for IG as LDIG55LW12LGcos!/9 in which all terms are previously defined. Theweigh of the glass, LG, consists of the weight of both
49、 glass lites.6.7.2 Determine the ERA.6.7.3 Determine the AR.6.7.4 Determine the required glass thickness for a single litein the IG unit from Fig. A1.1 (PB= 0.001) or Fig. A1.2 (PB=0.004) for the design load, ERA, and AR.6.7.5 Determine the approximate maximum center of glassdeflection as the deflection of one lite in the IG unit under thedesign load 0.9LDIGusing procedures from Practice E1300.6.8 Insulating Glass (IG) with Laminated Glass Lites ofEq
