1、Designation: E2751/E2751M 17aStandard Practice forDesign and Performance of Supported Laminated GlassWalkways1This standard is issued under the fixed designation E2751/E2751M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the yea
2、r of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice addresses elements related to load-bearingglass walkways, glass treads, and glass landings construc
3、tedwith laminated glass. This standard includes performance,design, and safe behavior considerations. It addresses thecharacteristics unique to glass and laminated glass. Issues thatare common to all walkways, such as slip resistance, areaddressed in existing referenced standards.1.2 This practice d
4、oes not address glass walkways con-structed with monolithic glass, glass block, insulating glassunits, glass tiles that are directly bonded to a non-glassstructural substrate, or glass walkways intended to supportvehicular traffic.1.3 The values stated in either SI units or inch-pound unitsare to be
5、 regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.4 This standard does not purport to address all of the
6、safety 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.1.5 This international standard was developed in accor-dance with inter
7、nationally recognized principles on standard-ization established in the Decision on Principles for 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:2C1036
8、 Specification for Flat GlassC1048 Specification for Heat-Strengthened and Fully Tem-pered Flat GlassC1172 Specification for Laminated Architectural Flat GlassE631 Terminology of Building ConstructionsE1300 Practice for Determining Load Resistance of Glass inBuildingsF1637 Practice for Safe Walking
9、SurfacesF2508 Practice for Validation, Calibration, and Certificationof Walkway Tribometers Using Reference Surfaces2.2 ANSI Standard:3A137.1 American National Standard Specification for Ce-ramic Tile3. Terminology3.1 DefinitionsFor definitions of general terms related tobuilding construction used i
10、n this practice, refer to Terminol-ogy E631.3.2 Definitions of Terms Specific to This Standard:3.2.1 duration of loadthe period of continuous applicationof a given load, or the aggregate of periods of intermittentapplications of the same load.3.2.1.1 DiscussionAny load duration longer than one hours
11、hall be considered a permanent load. Uniformly distributedlive loads shall have a load duration of at least one hour.Concentrated live loads shall have a load duration of at leastten minutes.3.2.2 ethylene vinyl acetate (EVA) interlayerco-polymerof ethylene and vinyl acetate used to permanently bond
12、 two ormore lites of glass.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 July 1, 2017. Published July 2017. Originally approvedin 2011. Last previou
13、s edition approved in 2017 as E2751/E2751M17. DOI:10.1520/E2751_E2751M-17A.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
14、 ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in a
15、ccordance 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.13.2.3 glass-clad polycarbona
16、te laminateassembly con-sisting of two or more lites of glass and one or more sheets ofpolycarbonate bonded by interlayers.3.2.4 ionomer interlayera partially neutralized copolymerof ethylene and acrylic or methacrylic acid, used to perma-nently bond two or more lites of glass.3.2.5 laminated glassa
17、n assembly consisting of two ormore lites of glass bonded by an interlayer.3.2.6 liquid resin interlayerliquid formulations, generallypolyester-, urethane-, or acrylic-based, that react to form solidinterlayers after being introduced between two lites of glass.3.2.7 polyurethane interlayerpolymer sh
18、eeting based onisocyanates and mostly polyester or acrylic polyols, or both.3.2.8 polyvinyl butyral (PVB) interlayerpolymer sheetingprepared from polyvinyl alcohol by reaction with butyralde-hyde used to permanently bond two or more lites of glass.3.2.9 post-breakage glass retentionthe ability of th
19、e bro-ken glass to remain in place so as to reduce cutting and piercinginjuries from the broken shards and to prevent fall through orglass fallout.3.2.10 slip resistantthe provision of adequate slip resis-tance to reduce the likelihood of slip for pedestrians usingreasonable care on the walking surf
20、ace under expected useconditions.3.2.11 supported glass walkwayany glass walkway with afree spanning section, including continuous or local multiplesupports at the edge or any location of the glass.3.2.12 walkway surfacesinterior and exterior walking sur-faces constructed and intended for pedestrian
21、 use, includingbut not limited to floors, ramps, sidewalks, and stair treads.4. Significance and Use4.1 Glass is a brittle material with different time andtemperature-dependent properties than other solid materialsused as walkways surfaces. Therefore, the type of glass is animportant consideration i
22、n the design and construction of glasstreads and glass landings constructed with laminated glass.4.2 Post-breakage glass retention is an important consider-ation in the design of a glass walkway system as a means ofminimizing tripping, cutting/piercing injuries, or fall-throughor fallout of the glas
23、s.4.3 The structural design shall be confirmed by calculationsby a licensed design professional in accordance with Section 5.4.4 If testing is required (see 4.4.1 4.4.3) to verifypost-glass breakage behavior of the glass walkway, the testingshall be in accordance with Section 6.4.4.1 For laminates w
24、ith two glass plies, verification testingis required.4.4.2 For laminates with more than two glass plies, verifi-cation testing is not required provided that calculations com-pleted in accordance with 4.3 demonstrate that the glassassembly has sufficient strength to sustain the full design loadwith a
25、ny one glass ply broken.4.4.3 When verifying post-breakage behavior bycalculation, allowable glass stress for 10 min load duration inaccordance with Table 1 shall be used for all load cases.4.5 The manufacturer or designer of glass walkway systemsshall provide installation directions and fabrication
26、 and instal-lation tolerances of their systems.4.6 The structural integrity of the glass walkway systemafter glass breakage shall be sufficient to support the designloads after any one glass ply is broken. If damage of any kindoccurs, the walkway shall be cordoned off and the installationshall be in
27、spected to ensure structural integrity and pedestriansafety of the system.5. Calculation Procedure5.1 Use established engineering methods, such as engineer-ing mechanics or finite element analysis, to determine glassassembly stresses and deflections. Such methods shall accountfor temperature, bounda
28、ry conditions, loading requirements,load duration, interlayer properties, and glass strength.5.2 Design Criteria:5.2.1 Assign nominal load conditions or combinations ofload conditions as required by the specifying authority.Additionally, the final design shall include consideration of aconcentrated
29、live load of at least 136 kg 300 lb applied to allglass walking surfaces in a 2600 mm24 in.2 area.5.2.2 Determine maximum allowable material stress.5.2.2.1 GlassRefer to Table 1 to determine allowableglass stress.(1) Use minimum glass thickness in accordance withSpecification C1036, Table 2, for des
30、ign purposes.5.2.2.2 InterlayerConsult the interlayer manufacturer forinterlayer material properties, load duration and temperaturebehavior. Typical interlayers are PVB, ionomer, liquid resin,EVA, and polyurethane.5.2.2.3 Other Laminate MaterialsConsult the supplier forproperties of other laminate m
31、aterials, such as polycarbonate.5.2.3 The structural support system shall provide sufficientstrength to support the combined applicable loads.5.2.4 Deflection of the floor members shall conform torelevant building code requirements.TABLE 1 Allowable Glass Stresses for Nominal Load ConditionsNOTE 1An
32、 allowable stress reduction factor of 0.5 is recommendedfor disruptive surface treatments, for example, sandblasting, unlessotherwise provided by the manufacturer. A glass stress reduction factormay be required for some acid etched or patterned glasses; consult themanufacturer.NOTE 2Values derived f
33、rom Practice E1300, Table X9.1 (seamededges), factored for load duration using Practice E1300, Equation X7.1,using n = 16 for annealed glass, n = 32 for heat strengthened glass, andn = 48 for tempered glass.Glass Type3-secMPa psi10-minMPa psi60-minMPa psiPermanentMPa psiAnnealed 18.3 2650 13.2 1902
34、11.7 1701 5.7 827Heat-strengthened36.5 5300 30.9 4482 29.2 4235 20.3 2944Tempered 73.0 10 600 65.3 9471 63.0 9137 49.4 7165E2751/E2751M 17a26. Post-breakage Verification Test Methods6.1 Assign nominal load conditions or combinations of loadconditions as required by the specifying authority.6.2 Test
35、for the dominant load case (uniform load orconcentrated load) as determined by calculations in accordancewith Section 5.6.3 Test the glass as a system with frame and attachments.6.4 For walkways with two supported edges, test a panelwith the largest span between supports. For walkways withthree or m
36、ore supported edges, test the sample size thatrepresents the most demanding or highest stress condition.6.5 Condition glass for at least four hours at the sametemperature at which it will be tested.6.6 Conduct testing at the maximum temperature for theintended use environment. When the intended end
37、use envi-ronment is unknown, conduct testing at 50 C and0C6 5 C.6.7 Concentrated Load Testing:6.7.1 Break any one glass lite to produce the most unfavor-able results. The worst case condition shall be determined byanalysis or all combinations of broken glass shall be tested.6.7.2 Apply the specified
38、 load over a 2600 mm24 in.2 areaat a rate of 45.4 kg 100 lb per minute up to the design loadand hold for a duration of 10 min.6.7.3 At the conclusion of testing, no additional glass pliesshall have broken.6.8 Uniform Load Testing:6.8.1 Break any one glass lite to produce the most unfavor-able result
39、s. Worst case condition shall be determined byanalysis or all combinations of broken glass shall be tested.6.8.2 Apply the specified uniform load at a rate of 30 psf-min up to the design pressure and hold for a duration of60 min.6.8.3 At the conclusion of testing, no additional glass pliesshall have
40、 broken.7. Other Considerations7.1 Slip Resistance:7.1.1 Walkway slip resistance should be commensurate withintended use, user populations, and foreseeable conditions andcontaminants. Non-level walkways, exterior walkways, walk-ways on which activities other than walking take place (forexample, athl
41、etic events), and walkways that cater to specialpopulations (for example, nursing homes, rehabilitation cen-ters) may require a higher level of slip resistance than otherwalkway surfaces. (See Practice F1637.)7.1.2 Appropriate levels of slip resistance can be accom-plished through a variety of glass
42、 surface treatments, includingsandblasting, acid-etching, ceramic frit, embossing, kilncasting/fusing, and other processes designed to treat the walk-ing surface.7.1.3 The selection of the slip resistant treatment shall bemade according to the intended use and desired durability ofthe walking surfac
43、e.7.1.4 Evaluate and report the slip resistance of manufac-tured glass walkway products in one of the following ways:7.1.4.1 In accordance with ANSI A137.1.7.1.4.2 Testing using tribometers (slip testing devices) dem-onstrated to be valid in accordance with Practice F2508.7.1.4.3 Test methods requir
44、ed or accepted by applicablelocal building codes and safety standards.7.1.4.4 As specified by the designer.7.1.5 Certifications of slip resistance shall be conducted byindependent testing laboratories or agencies.7.2 Materials:7.2.1 Glass SelectionGlass selection is based on manyfactors, including s
45、trength, fabrication, durability, aesthetics,cost, and glass post-breakage behavior.7.2.1.1 Annealed GlassRefer to Specification C1036 forrequirements pertaining to flat glass.7.2.1.2 Heat-Strengthened GlassRefer to SpecificationC1048 for requirements pertaining to heat-strengthened glass.7.2.1.3 Te
46、mpered GlassRefer to Specification C1048 forrequirements pertaining to tempered glass.7.2.1.4 Laminated GlassRefer to Specification C1172 forrequirements pertaining to laminated glass.7.2.2 Interlayer SelectionInterlayer selection is based onmany factors, including strength, fabrication, durability,
47、aesthetics, cost, and glass post-breakage behavior.7.3 Structural Support System:7.3.1 The glass edge support system shall be sufficientlystiff to limit the deflection of the supported glass edges underthe design load to no more than L/500 of their lengths, whereL is the supported length of the glas
48、s, unless analysis takinginto account frame deflection effects on glass stress is carriedout in combination with the design loads in accordance withSection 5.7.3.2 The glass shall be cushioned to prevent direct contactwith the glass support system.7.4 Dynamic Use Considerations:7.4.1 The licensed de
49、sign professional shall consider thenecessity of a glass floor systems vibration review, and ifnecessary, perform such review. Considerations may includesystem continuity, supports, and deflection compatibility withadjacent structures.7.5 Fire Resistance Requirements:7.5.1 Glass walkways shall provide a fire rating whenrequired by the authority having jurisdiction.7.6 Visual Cues:7.7 Glass walkways present a special challenge in balancingthe visual characteristics of glass with considerations of safety.
