1、Designation: D7147 11Standard Specification forTesting and Establishing Allowable Loads of Joist Hangers1This standard is issued under the fixed designation D7147; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. 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 specification covers a procedure for evaluatingmetal devices used for wood-to-wood, wood-to-concrete,wood-to-concrete ma
3、sonry, and wood-to-steel connections.This method is intended for use with devices used to connectjoists, beams, and girders together. These devices are com-monly described as joist hangers.1.2 This specification describes test methods for evaluatingthe capacities of joist hangers subject to vertical
4、 and torsionalloading.1.3 This specification provides a method of assigning allow-able loads to joist hangers based on measured strength anddeformation characteristics. Information obtained by the pro-visions of this specification is applicable to design when usingthe Allowable Stress Design method.
5、1.4 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 D
6、ocuments2.1 ASTM Standards:2C31/C31M Practice for Making and Curing Concrete TestSpecimens in the FieldC39/C39M Test Method for Compressive Strength of Cy-lindrical Concrete SpecimensC1314 Test Method for Compressive Strength of MasonryPrismsD9 Terminology Relating to Wood and Wood-Based Prod-uctsD2
7、395 Test Methods for Specific Gravity of Wood andWood-Based MaterialsD3737 Practice for Establishing Allowable Properties forStructural Glued Laminated Timber (Glulam)D4442 Test Methods for Direct Moisture Content Measure-ment of Wood and Wood-Base MaterialsD5055 Specification for Establishing and M
8、onitoring Struc-tural Capacities of Prefabricated Wood I-JoistsD5456 Specification for Evaluation of Structural CompositeLumber ProductsD7438 Practice for Field Calibration and Application ofHand-Held Moisture MetersE4 Practices for Force Verification of Testing MachinesE8 Test Methods for Tension T
9、esting of Metallic MaterialsE575 Practice for Reporting Data from Structural Tests ofBuilding Constructions, Elements, Connections, and As-sembliesF606 Test Methods for Determining the Mechanical Prop-erties of Externally and Internally Threaded Fasteners,Washers, Direct Tension Indicators, and Rive
10、tsF1470 Practice for Fastener Sampling for Specified Me-chanical Properties and Performance InspectionF1575 Test Method for Determining Bending Yield Mo-ment of Nails2.2 Other Standards:ANSI/AF the measuredlength, diameter; and strength properties required in 7.4,12.1.5 A description of the concrete
11、 or masonry properties,including measured properties as required in 7.2, if concrete ormasonry was used,12.1.6 A description of the load transfer block, other block-ing, low-friction materials, reinforcement, and any deviationsfrom the standard test setup shown in Figs. 3 and 4,12.1.7 Data on load-d
12、eflection, including the load at the0.125 in. (3.18 mm) deflection limit, and the maximum testload observed,12.1.8 Type and location of failure of the specimen,12.1.9 Number of replications including a description ofreplications not used as allowed in 11.7,12.1.10 Loading procedure details, includin
13、g preload, loadrate, and time to maximum load, and12.1.11 Details of any deviations from the prescribed testsetup and test procedures as outlined in this specification.13. Allowable Joist Hanger Loads Limited by Test13.1 Joist hanger design values limited by test shall belimited to the materials tes
14、ted, except as otherwise provided inSection 13. For application to materials used in construction,the construction materials shall satisfy 13.1.1-13.1.4.13.1.1 WoodAll wood materials shall be of structuralquality with allowable values substantiated by accepted proce-dures, such as those found in Sec
15、tion 2.13.1.2 SteelAll production steel material shall meet orexceed a specified minimum yield strength, a specified mini-mum ultimate strength, and a specified minimum thickness.13.1.3 FastenersFasteners used for field installation shallmeet or exceed minimum specified cross-sectional dimensions(fo
16、r example, diameter or width and thickness), length, otherrelevant dimensions, and relevant material properties.13.1.4 Concrete and MasonryAll concrete and masonrymaterials shall have structural properties that meet or exceed aminimum specified compression strength.13.2 Allowable loads for joist han
17、gers based upon test shallbe the lesser of the values determined in 13.3 and 13.4.Adjustments to test results shall be made in accordance with13.5.13.2.1 The results of all load tests except those testsexcluded per 11.7 shall be used to determine the allowable loadcapacity of the joist hanger.13.3 T
18、est Strength Limit:13.3.1 The ultimate load rating shall be the lowest ultimateload per joist hanger divided by 3.0 if less than six replicatesare tested. The ultimate load rating shall be the averageultimate load per joist hanger divided by 3.0 when six or morereplicates are tested. See 13.5 for ad
19、justments to test results.13.4 Test Deflection Limit:13.4.1 For all vertical load tests, the load at 0.125-in.deflection shall be recorded for each hanger. The test deflectionlimit load shall be the average of all of these loads. The load atthe specified deflection limit shall be permitted to be int
20、erpo-lated from the test data.13.5 Adjustments to Test Strength Limit:13.5.1 The resulting test values shall be multiplied by thelowest of the adjustment factors determined in 13.5.2-13.5.4.NOTE 3The adjustments outlined in 13.5 are based upon sawn lumberperformance and are not applicable to SCL. As
21、 outlined in 8.1, SCLmembers selected for testing should conservatively represent the perfor-mance level used to establish its related fastener design properties. Nofurther adjustment of the test data should be undertaken.13.5.1.1 The following definitions apply to adjustment fac-tors in 13.5.2-13.5
22、.4.Ajoist= bearing area between the joist and the joisthanger, in.2.D7147 115Aheader= the area on the header subject to compres-sion perpendicular-to-grain from thehanger.Fc, nominal= 2250 x Gnominal 480, psi.Fc, tested= 2250 x Gtested 480, psi.Fu, spec= ultimate strength of the connector steelfrom
23、the manufacturers specifications, psi(# Fu, tested).Fu, tested= measured ultimate strength of the connec-tor steel used in the test specimens, psi.Fyb, nominal= bending yield strength of the connectorfasteners published in the ANSI/AF connectors; connectors for wood; hang-ers; hanger allowable loads
24、; hanger capacities; hanger test;hanger testing; joist hangers; metal connectors; structuralconnectors; wood connections; wood connectors; wood towood connectorsD7147 118APPENDIXES(Nonmandatory Information)X1. TORSIONAL TESTINGX1.1 Test SpecimensTorsional Moment Test AssembliesX1.1.1 A specimen shal
25、l consist of a joist supported be-tween two headers by the hanger devices to be evaluated. SeeFigs. X1.1 and X1.2.X1.1.2 Joist and headers shall have a length sufficient topermit loading of the joist hanger without excessive deforma-tion of the test specimen. Minimum joist length shall be 18 in.(460
26、 mm). Refer to 9.2-9.7 for other requirements.X1.2 ProcedureTorsional Moment TestX1.2.1 The joist shall be loaded to induce a torsionalmoment in the joist hanger. The joist shall be loaded mid spanat least 12 in. (305 mm) from the top of the joist. See Figs.X1.1 and X1.2.X1.2.2 Horizontal movement o
27、f the joist with respect to theheader shall be measured with dial gages or other measuringdevices at the top and bottom of each end of the joist. The dialFIG. X1.1 Torsional Moment Test SetupD7147 119gage shall be within 1.5 in. (38 mm) of the end of the joist or12 in. of the hanger strap, and withi
28、n 1 in. (25 mm) of the topor bottom of the joist. The location of the gages and distancebetween them shall be recorded. The slip shall be recorded tothe nearest 0.001 in. (0.02 mm) at a sufficient number of loadlevels to permit establishment of a load-deformation curve.X1.2.3 An initial load, or pre
29、load, shall be applied to thejoist to seat the connector. This preload shall be no more than20 % of the ultimate load. This load shall then be removed andthe dial gages shall be set to zero.X1.2.4 The torsional load shall be applied to the center ofthe joist. Record the movement of all gages until o
30、ne gage hasregistered a movement of at least38 in. (10 mm) or failure,whichever comes first.X1.2.5 Load shall be applied at a rate as specified in Section11.X1.3 Torsional Moment Design LoadsX1.3.1 Test Strength LimitThe ultimate torque per hangerfor torsional moment capacity tests illustrated in Fi
31、g. X1.1 isdetermined by selecting the torsional test, which gives thelowest ultimate torque per hanger. This load shall then bedivided by 3.0 to determine an allowable load based on teststrength.X1.3.2 Torsional Deformation LimitJoist hanger rotationshall be limited to a maximum rotation of 1.2 as m
32、easuredbetween the joist and the header. The allowable torque basedon test deformation limit shall be taken as the average of allspecimens tested, on a per hanger basis, at the specifieddeformation limit of 1.2.X1.3.2.1 For torsion tests, joist rotation, u, may be calcu-lated asu5sin21Sdtop1dbottomd
33、D(X1.1)where:u = joist rotation,dtop= horizontal deflection at top dial gage,dbottom= horizontal deflection at bottom dial gage, andd = distance between dial gages.Horizontal deflection of the top of the joist and horizontaldeflection of the bottom of the joist are taken as positive inopposite direc
34、tions, for example, if the joist rotates about itscentroid, both deflection measurements will be the same sign.When the top and bottom dial gages show movement in thesame direction, the deflection measurements will be of oppo-site sign.X1.3.3 The allowable design torque for the joist hangershall be
35、limited to the lesser value determined in X1.3.1 andX1.3.2.X2. COMMENTARYX2.1 This standard began as a revision of the joist hangertest provisions of Test Methods D1761-88(2006). It wasseparated from Test Methods D1761 due to its inclusion ofadditional provisions specific to joist hangers, and the j
36、oisthanger provisions in Test Methods D1761 were removed inTest Methods D1761-06.X2.2 Additional references that may be useful are shownbelow.FIG. X1.2 Torsional Moment Test Setup (Perspective)D7147 1110ADDITIONAL REFERENCES(1) C90 Specification for Hollow Load-Bearing Concrete Masonry Units(2) C270
37、 Specification for Mortar for Unit Masonry(3) D245 Practice for Establishing Structural Grades and Related Allow-able Properties for Visually Graded Lumber(4) ANSI/ASME B18.2.12010: Square, Hex, Heavy Hex, and AskewHead Bolts and Hex, Heavy Hex, Hex Flange, Lobed Head, and LagScrews (Inch Series), 2
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40、ndardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Com
41、mittee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddr
42、ess or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).6Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave., New York, NY 10016-5990, http:/www.asme.org.D7147 1111
