ASTM_C_947_-_03_2016.pdf

Designation:C94703(Reapproved 2016)Standard Test Method forFlexural Properties of Thin-Section Glass-Fiber-ReinforcedConcrete(Using Simple Beam With Third-Point Loading)1This standard is issued under the fixed designation C947;the number immediately following the designation indicates the year oforiginal adoption or,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 test method covers determination of the flexuralultimate strength in bending and the yield strength of glass-fiber reinforced concrete sections by the use of a simple beamof 1.0 in.(25.4 mm)or less in depth using third-point loading.1.2 The values stated in inch-pound units are to be regardedas the standard.The values given in parentheses are forinformation only.1.3 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 Documents2.1 ASTM Standards:2C1228 Practice for Preparing Coupons for Flexural andWashout Tests on Glass Fiber Reinforced ConcreteD76 Specification for Tensile Testing Machines for TextilesE4 Practices for Force Verification of Testing Machines3.Significance and Use3.1 Flexural properties determined by this test method areuseful for quality control of glass-fiber reinforced concreteproducts,ascertaining compliance with the governingspecifications,research and development,and generating datafor use in product design.4.Apparatus4.1 Testing MachineAproperly calibrated testing machinethat can be operated at constant rates of crosshead motion andin which the error in the force measuring system shall notexceed 61.0%of the maximum force expected to be measuredshall be used.The testing machine shall be equipped with adeflection measuring and recording device.The stiffness of thetesting machine shall be such that the total elastic deformationof the system does not exceed 1.0%of the total deflection ofthe test specimen during the test,or appropriate correctionsshall be made.The force-indicating mechanism shall beessentially free of inertial lag at the crosshead rate used.Theaccuracy of the testing machine shall be verified in accordancewith Practices E4 and Specification D76.4.2 Loading Noses and SupportsThe loading noses andsupports shall have cylindrical surfaces.In order to avoidexcessive indentation or failure due to stress concentrationdirectly under the loading noses or supports,the radius of thenoses and supports shall be at least 0.25 in.(6.35 mm).See Fig.1 for loading configuration.The arc of the loading noses andsupports,in contact with the specimen,shall be sufficientlylarge to prevent contact of the specimen with the sides of thenoses.Neoprene pads,approximately116in.(1.6 mm)thick,may be placed between the loading noses and the test specimenfor uniform load distribution across the width of the specimen.However,neoprene pads should not be used if deflectionmeasurements are to be made,as the compression of theneoprene will distort the measurements.4.3 Loading Head and Support ApparatusLoading noses,supports,and their respective holding devices shall be designedto allow rotation to occur about axes that lie in horizontalplanes of the loading apparatus as shown in Fig.1.Thisconfiguration of loading head and support apparatus willensure that forces applied to the specimen will be initiallyperpendicular to the surfaces of the specimen and appliedwithout eccentricity.4.4 Specimen Depth and Width Measuring DeviceA cali-per or micrometer or other suitable device that is able tomeasure sample depth accurate to 0.005 in.(0.13 mm)andwidth accurate to 0.01 in.(0.25 mm).5.Sampling5.1 Test boards shall be manufactured in accordance withgoverning specifications.1This test method is under the jurisdiction of ASTM Committee C27 on PrecastConcrete Products and is the direct responsibility of Subcommittee C27.40 on GlassFiber Reinforced Concrete.Current edition approved April 1,2016.Published May 2016.Originallyapproved in 1981.Last previous edition approved in 2009 as C947 03(2009).DOI:10.1520/C0947-03R16.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Test Specimen6.1 Six test specimens shall be prepared in accordance withPractice C1228.6.2 The test specimen shall have a ratio of the specimenmajor span length to the specimen depth between 16 to 1 and30 to 1.The total specimen length shall be a minimum of 1 in.(25 mm)longer than the specimens major span.Nomin