ASTM E529-2004(2011) 8750 Standard Guide for Conducting Flexural Tests on Beams and Girders for Building Construction《进行房屋建筑用桁条和大梁弯曲试验的标准指南》.pdf

1、Designation: E529 04 (Reapproved 2011)Standard Guide forConducting Flexural Tests on Beams and Girders forBuilding Construction1This standard is issued under the fixed designation E529; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio

2、n, 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This guide covers the

3、flexural testing of beams andgirders under simulated service conditions to determine theirstructural performance characteristics. Methods following thisguide are intended primarily for constructions that may notconform with the relatively simple assumptions upon whichwell-known flexural theories are

4、 based. In some cases, they arealso suitable for determining the structural adequacy of thedesign, materials, connections, and fabrication techniques. Themethods are not intended for use in routine quality controltests.1.2 This standard does not purport to address all of thesafety concerns, if any,

5、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. For specificprecautionary statement, see 7.1.2. Referenced Document2.1 ASTM Standards:2E575 Pra

6、ctice for Reporting Data from Structural Tests ofBuilding Constructions, Elements, Connections, and As-sembliesE631 Terminology of Building Constructions3. Terminology3.1 For definitions of terms used in this standard, refer toTerminology E631.4. Significance4.1 This guide provides a general procedu

7、re for conductingflexural load tests on beams and girders of all types. Strength,stiffness, creep, or other useful properties may be obtained.When round-robin tests are to be conducted, a standardized setof procedures conforming to this guide should be agreed uponby the participants prior to testing

8、 to ensure a uniform basis forcomparison.5. Types of Tests5.1 The flexural test is categorized as either a proof test oran ultimate load test. A proof test is intended to give assurancethat the member will support a certain minimum short-termload, or to determine the deflection and recovery resultin

9、g fromthe application and removal of such a load. In carrying on a testto failure (ultimate load), more detailed information can beobtained, such as the proportional limit, yield point, ultimatecapacity, mode of failure, load-deflection characteristics, andthe adequacy of connectors and connections.

10、5.2 Both laboratory and field tests are acceptable.5.3 The types of tests described above apply to beamssubjected to short-term static loads. If cyclic, dynamic, orlong-term sustained load tests are undertaken, care should betaken to ensure that procedures are consistent, that the testsetup is relia

11、ble, and that load points cannot shift betweencycles or impacts.6. Apparatus6.1 Loading method, type of test equipment, type of instru-mentation, and so forth, are not specified, but are discussed ingeneral terms, with the final choices being left to the discretionof the testing agency or controllin

12、g regulatory body.7. Safety Precautions7.1 Tests of this type can be dangerous. Equipment andfacilities must be designed with ample safety factors to assurethat it is the specimen that fails and not the test apparatus orfacilities. Observers and sensitive instrumentation must be keptaway from beams

13、when loading to failure or in a range whereperformance is unknown. Gravity loading with concreteblocks, metal bars, sand, or similar materials can be veryhazardous at failure as collapse may be sudden and complete.1This guide is under the jurisdiction of ASTM Committee E06 on Performanceof Buildings

14、 and is the direct responsibility of Subcommittee E06.11 on Horizontaland Vertical Structures/Structural Performance of Completed Structures.Current edition approved April 1, 2011. Published May 2011. Originallyapproved in 1975. Last previous edition approved in 2004 as E529 04. DOI:10.1520/E0529-04

15、R11.2For 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO

16、Box C700, West Conshohocken, PA 19428-2959, United States.8. Number of Tests8.1 The number of like beams required for the tests willvary with the desired accuracy and reliability of the informa-tion to be obtained and with the purpose of the tests. Thenumber chosen should be compatible with the purp

17、ose of thetests and agreeable to all parties concerned regarding thesignificance of the results. However, no fewer than twoidentical tests should be performed.9. Test Specimen9.1 Specimens shall be typical of those anticipated inservice or as required for the purpose of the tests. Materials,fabricat

18、ion, fasteners, connections, and so forth shall be repre-sentative. If the materials used require time to come to fullstrength, sufficient time shall be allowed between fabricationand testing for proper curing. This period of time will varybetween materials but should be no less than that specified

19、byapplicable building codes or in the manufacturers recommen-dations.10. Preparation of Apparatus10.1 Test Set-up:10.1.1 Loads are applied using a testing machine, hydraulicrams, dead weights, or by other appropriate means. Set-upsmay be designed to test the specimens either horizontally orverticall

20、y. It is recommended that the specimens be tested inthe same position as assumed in the design. Regardless of theposition of the member in the test fixture, the loading apparatusmust be capable of applying the same forces, shears, andmoments that the actual member in its proposed usage isintended to

21、 resist.10.1.2 Provide supports that are capable of carrying thereactions without significant deformation or lateral movement.They are to be typical of those anticipated in service, or asrequired to satisfy the purpose of the tests. If the expectedservice conditions are unknown, provide supports tha

22、t simulatethe most stringent conditions likely to occur, or that wouldinduce the most critical effects on the specimens.10.1.3 Weigh materials used for gravity loading to anaccuracy of 61 %. Other types of loading equipment shall becapable of applying loads with similar accuracy.10.2 Instrumentation

23、 and Measurement:10.2.1 Calibrate instrumentation and load-measuring de-vices to 61 % accuracy. In some indirect methods of loadmeasurement, the load on the beam and that indicated may notbe quite the same. Better accuracy in load determination isobtained when the magnitude is directly indicated. Th

24、is can bedone by the use of proving rings or load cells at the reactionsor at the points of loading, or by adequate mechanical orelectronic devices.10.2.2 Deformation Readings:10.2.2.1 Deformation readings can be obtained in a numberof ways. One of the simplest methods is by use of a taut wireplaced

25、 along the length of the beam. When a taut wire is used,the mountings for the wire should be above the two endsupports on the beam at or close to the neutral axis. Maintaina reasonably constant tension on the wire by means of pulleysand weights, springs, or by other suitable means. Take readingsfrom

26、 a scale and mirror attached to the beam at the measure-ment points. Read the scale by lining up the taut wire with itsreflection in the mirror.10.2.2.2 Other common methods of measuring deforma-tions involve the use of micrometer dial gages or linearvariable differential transformers attached to a

27、suitable refer-ence bar and bearing at the desired points on the beam. Mountthe reference bar for supporting the deflection-measuringapparatus on the beam above the two end supports at or closeto the neutral axis. Deformations can also be determined byusing a surveyors level and reading scales attac

28、hed to thebeam. In all cases, the method used shall compensate for anysettlement of the reaction supports.10.2.3 Strain readings can be taken by any of the manystrain indicators and gaging systems commercially available.Follow a consistent procedure in taking strain readings toensure results that wi

29、ll produce reliable stress-strain data.NOTE 1The use of strain gages on wood beams should be approachedwith great caution. Local variation in the stiffness of wood can cause asignificant difference between the strain measured on the surface of thebeam and the true strain through the entire beam dept

30、h.11. Loading Procedure11.1 Support, brace laterally, and load the beam in a mannerthat closely simulates service conditions or satisfies the intentof the test.11.2 Before the test is begun, document any defects or otherexisting characteristics that could be confused as being causedby the test.11.3

31、Apply and remove the load or loads in equal incre-ments or continuously and at as uniform a rate a possible.Record the load, load rate, deformations, and other desired dataat each increment or decrement. Choose the load intervals sothat sufficient measurements can be made to develop a satis-factory

32、load-deformation or stress-strain curve. Usually thiscan be achieved when each of the increments of load does notexceed 20 % of the service dead plus live load. This shouldprovide approximately ten or more points on the load versusdeformation curve at failure. Select a rate of load applicationthat i

33、s consistent with the purpose of the tests. When loads areapplied by a testing machine, either a constant rate of loadingor constant rate of straining is used.11.4 Except in the instance of impact tests, after eachincrement of load is applied, maintain the load level at asconstant a level as possibl

34、e for a period of 5 min (see Note 2).11.4.1 Take deformation readings as soon as practical afterload application, at the end of the 5-min period under constantload, and immediately and at the end of the 5-min period afterany partial or complete load release. Plot initial and 5-minreadings in the for

35、m of load-deformation curves. Maintaincomplete load-deformation-time records throughout the test.11.4.2 If application of a given load is required for a certainperiod, such as 24 h, take deformation readings at the begin-ning, and at equal intervals during this period, to allow thesatisfactory plott

36、ing of a time-deformation curve for thecomplete period.E529 04 (2011)2NOTE 2Reasons for the 5-min application of constant-level incrementloads are as follows:(1) To permit the assembly to come to a substantial rest prior to takingthe second set of readings. (Depending upon the method employed forapp

37、lying the test load, it may be necessary to continue, at a reduced rate,the motion of the loading device in order to maintain the constant loadlevel during the 5-min period.)(2) To provide sufficient time for making all observations. (Longer timeintervals may be required under certain conditions.)(3

38、) To observe any time-dependent deformation or load redistributionor both, and to record accurately the load level when time-dependentdeformation starts, that is, at the divergence of the immediate and delayedload-deformation curves. This load level may, under certain conditions,have an important be

39、aring on the design load.(4) To be able to stop the test, if this should be desirable, prior to totalfailure or after initial failure has been anticipated as a result of theobservations.(5) To assure uniformity in test performance and consistency in testresults.11.5 Note and record visual and audibl

40、e signs of distress inthe beam, any deformation at connections and joints, and themode of failure. Make a photographic record of the failuremade and other noteworthy events.11.6 Auxiliary TestsTo aid in the interpretation of theresults, it is generally desirable and in many cases mandatoryto determi

41、ne the inherent properties of the materials, fasten-ings, and connectors used in the specimens. Perform allauxiliary tests in accordance with applicable ASTM standards.12. Report12.1 The report shall conform to Practice E575.13. Precision and Bias13.1 No statement is made on the precision or on the

42、bias oftest methods based on this guide, since no standard set ofprocedures is specified.14. Keywords14.1 beams; flexural test; girdersASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this stand

43、ard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andi

44、f not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, wh

45、ich you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee 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,

46、United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress 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/).E529 04 (2011)3