1、Designation:E246105 (Reapproved 2011) Designation: E2461 12Standard 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 o
2、r, 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 thickness of glass installed in
3、airport traffic control towers (ATCT) to resista specified design loading with a selected probability of breakage less than or equal to either 1 lite per 1000 or 4 lites per 1000at the first occurrence of the design wind loading.1.2 The procedures apply to common outward sloping cab glass designs fo
4、r which the specified loads do not exceed 10 kPa (210psf).1.3 The procedures assume control tower cab glass has an aspect ratio no greater than 2.1.4 The procedures assume control tower cab glass has an area no less than 1.86 square metres (20 square feet).1.5 The procedures apply only to annealed m
5、onolithic, annealed laminated, or annealed insulating glass having a rectangularor trapezoidal shape.1.6 The use of the procedures assumes the following:1.6.1 Annealed monolithic and annealed laminated glass installed in ATCTs shall have continuous lateral support along twoparallel edges, along any
6、three edges, or along all four edges;1.6.2 Insulating glass shall have continuous lateral support along all four edges; and1.6.3 Supported glass edges are simply supported and free to slip in plane.1.7 The procedures do not apply to any form of wired, patterned, etched, sandblasted, or glass types w
7、ith surface treatments thatreduce the glass strength.1.8 The procedures do not apply to any form of heat treated glass, chemically strengthened glass, or any type of glass withsurface treatments intended to increase the glass strength.1.9 The procedures address the determination of thickness and con
8、struction type to resist a specified design wind load at aselected probability of breakage. The final glass thickness and construction determined also depends upon a variety of other factors(see 5.3).1.10 These procedures do not address blast loading on glass.1.11 The values stated in SI units are t
9、o be regarded as standard. The values given in parentheses are mathematical conversionsto inch-pound units that are provided for information only and are not considered standard.1.12 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the resp
10、onsibilityof the user of this standard to establish appropriate safety and health practices and to determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C162 Terminology of Glass and Glass ProductsC1036 Specification for Flat GlassE631 Terminolo
11、gy of Building ConstructionsE1300 Practice for Determining Load Resistance of Glass in Buildings2.2 American Society of Civil Engineers Standard:3ASCE 7 Minimum Design Loads for Buildings and Other Structures1This practice is under the jurisdiction of ASTM Committee E06 on Performance of Buildings a
12、nd is the direct responsibility of Subcommittee E06.51 on Performanceof Windows, Doors, Skylights and Curtain Walls.Current edition approved Oct.April 1, 2011.2012. Published November 2011.May 2012. Originally approved in 2005. Last previous edition in 20052011 asE2421 05 (2011). DOI: 10.1520/E2461-
13、05R11.10.1520/E2461-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3Available from American Society of
14、Civil Engineers (ASCE), 1801 Alexander Bell Dr., Reston, VA 20191, http:/www.asce.org.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to
15、 adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Cons
16、hohocken, PA 19428-2959, United States.3. Terminology3.1 Definitions:3.1.1Refer to Terminology3.1.1 For definitions of general terms related to building construction used in this test method refer to Terminology E631foradditional terms used in these procedures. , and for general terms related to gla
17、ss 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 of uniform 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 dimension to the short dimension for rectangular glass or the ratio of the longdimension to the short dimension of the rectangle that completely encloses trapezoidal glass. In these procedures, AR is alwaysequal to or greater than 1.0.NOTE 1The rectangle that completely encloses t
19、he trapezoid has two sides parallel to the horizontal edges of the trapezoid and the other two sidesperpendicular to the horizontal edges of the trapezoid. All dimensions shall be measured from edge to edge of glass.3.2.3 equivalent rectangular area (ERA), nthe product of the longest horizontal glas
20、s dimension and the length of the edgeperpendicular to the horizontal dimension in the plane of the glass. All dimensions shall be measured from edge to edge of glass.3.2.4 designated thickness for laminated glass (LG), nthe designated thickness for LG as Table 1 specifies.3.2.5 designated thickness
21、 for monolithic glass, nthe designated or nominal thickness commonly used in specifying aparticular glass product, based on the minimum thicknesses presented in Table 2 and Specification C1036.3.2.6 glass breakage, nthe fracture of any lite or ply in monolithic, laminated, or insulating glass result
22、ing from stress thatan applied uniform lateral load induces.3.2.7 insulating glass (IG) unit, nconsists of any combination of two glass lites, as defined herein, that enclose a sealed spacefilled with air or other gas.3.2.8 laminated glass (LG), na flat-lite of uniform thickness that is fabricated b
23、y bonding two or more monolithic glass litesor plies of equal thickness, as defined herein, together with polyvinyl 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-se
24、cond duration load used to design glass forATCT cabs. Equations used hereinfor computing magnitudes for design loads adjust glass self weight to a magnitude consistent with a 3-second duration.3.2.10.2 specified design load, nthe magnitude in kPa (psf), type (for example, wind or self-weight) and du
25、ration of the load.The wind load has a duration of approximately 3 seconds. Glass self-weight (Table 2) has a long duration, typically equal to thein-service life of the window glass lite. Earth facing cab glass is only subjected to wind load and its self-weight.TABLE 1 Thickness Designations for La
26、minated GlassLaminated glassdesignation, t,mm (in.)Laminated glass constructionnominal thickness, mm (in.)glass/PVB/glassLaminated glass thicknessdesignation 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 (
27、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) 12 (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)1
28、9 (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)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)E2461 1223.2.10.3 long duration load, nany
29、 load lasting approximately 30 days or longer.3.2.10.4 short duration load, nany load lasting approximately 3 seconds, such as, wind load.3.2.11 minimum thickness of monolithic glass, nthe minimum allowable thickness associated with a nominal or designatedglass thickness as given in Table 2 and Spec
30、ification C1036.3.2.12 probability of breakage (Pb), nthe theoretical fraction of glass lites or plies that would break at the first occurrence ofthe resistance load, typically expressed in lites per thousand.4. Summary of Practice4.1 The use of these procedures requires a specified design load that
31、 shall consist of the wind load and the factored lateralcomponent of glass weight. The total design load shall not exceed 10 kPa (210 psf).4.2 The procedures specified herein facilitate determination of the thickness of an annealed window glass construction requiredto resist the specified design loa
32、ding for the selected probability of breakage.4.3 This standard procedure uses methods in Practice E1300to determine the approximate lateral deflection of the geometriccenter of the window glass construction. Annex A2 provides deflection charts for laminated glass thicknesses larger than thosecontai
33、ned in Practice E1300.5. Significance and Use5.1 This standard procedure facilitates determination of the thickness of a glass construction required to resist a specified designload with a selected probability of breakage.5.2 This standard procedure addresses the following glass constructions: annea
34、led monolithic, annealed laminated, andinsulating glass fabricated with annealed monolithic or annealed laminated glass, or both.5.3 Use of these procedures assume:5.3.1 The glass is free of edge damage and is properly glazed,5.3.2 The glass has not been subjected to abuse,5.3.3 The surface conditio
35、n of the glass is typical of glass that has been in service for several years, and is significantly weakerthan freshly manufactured glass due to minor abrasions on exposed surfaces,5.3.4 The glass edge support system is sufficiently stiff to limit the lateral deflections of the supported glass edges
36、 to less than1/175 of their lengths. The specified design load shall be used for this calculation, and5.3.5 The center of glass deflection shall not result in loss of edge support. Typically maintaining center of glass deflection ator below the magnitude of three times the nominal glass thickness as
37、sures that no loss of edge support will occur.5.4 Many other factors affect the selection of glass type and thickness. These factors include but are not limited to: thermalstresses, the effects of windborne debris, excessive deflections, behavior of glass fragments after breakage, seismic effects, h
38、eatflow, edge bite, noise abatement, potential post-breakage consequences, and so forth. In addition, considerations set forth in federal,state, and local building codes along with criteria presented in safety glazing standards and site specific concerns may control theultimate glass type and thickn
39、ess selection.6. Procedure6.1 Select a probability of breakage, glass type or construction, and glass thickness(es).6.2 Compute the design load for monolithic or single laminated glass according to:LD5 LW1 2LGcosu (1)E2461-12_1TABLE 2 Thickness Designations, Minimum Glass Thickness,and Unit Self-Wei
40、ghtNominal thickness ordesignation. mm (in.)Minimum thickness, mm(in.)Glass weightPa (psf)2.7 (lami) 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)
41、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 (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
42、designation.E2461 123where:LD= denotes the design load,LW= denotes the wind load,LG= denotes the weight of the glass, andu = denotes the acute angle the glass makes with the horizontal. For monolithic or single laminated glazing, the user shallobtain LGfrom Table 2 for the nominal glass thickness. F
43、or insulating glass, LGshall consist of the weights of both glasslites as determined from Table 2.6.3 Monolithic Single Glazing Continuously Supported Along 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. A
44、1.2 PB= 0.004) for the design load, ERA, andAR.6.3.4 Determine the approximate maximum center of glass deflection using procedures from Practice E1300.6.4 Single Laminated Glazing Continuously Supported Along all Four Edges:6.4.1 Determine the ERA.6.4.2 Determine the AR.6.4.3 Determine the required
45、glass thickness from Fig. A1.3 (PB= 0.001) or Fig. A1.4 (PB= 0.004) for the design load, ERA,and AR.6.4.4 Determine the approximate maximum center of glass deflection using procedures from Practice E1300.6.5 Monolithic Single Glazing Simply Supported Continuously Along Two Opposite Sides or any Thre
46、e Sides:6.5.1 Determine the Unsupported 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 glass deflection using procedures from Practice E1300.6.6 Single Lam
47、inated Glazing Simply Supported Continuously 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 maxim
48、um center of glass deflection using procedures from Practice E1300.6.7 Insulating Glass (IG) with Monolithic Glass Lites of Equal (Symmetric) Glass Type and Thickness.6.7.1 Compute the design load for IG as LDIG5 5LW1 2LGcosu!/9 in which all terms are previously defined. The weighof the glass, LG, c
49、onsists of the weight of both 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 lite in 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 glass deflection as the deflection of one lite in the IG unit under the designload 0.9LDIGusing procedures from Practice E1300.6.8 Insulating Glass (IG) wit
