1、Designation: C1716/C1716M 11Standard Specification forCompression Testing Machine Requirements for ConcreteMasonry Units, Related Units, and Prisms1This standard is issued under the fixed designation C1716/C1716M; the number immediately following the designation indicates theyear of original adoptio
2、n or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification provides minimum design standardsfor testing machines u
3、sed to measure the compressive strengthof concrete masonry units, related units, and masonry prismscovered under Test Methods C140 and C1314.1.2 The text of this standard references notes and footnoteswhich provide explanatory material. These notes and footnotes(excluding those in tables and figures
4、) shall not be consideredas requirements of this standard.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalu
5、es from the two systems may result in non-conformancewith the standard.1.4 This specification shall be used to determine the maxi-mum allowable specimen size and the maximum allowableload limits on a specific specimen for any test machine. Theselimits are based on deflection of the bearing surfaces
6、and themachine load frame. These limits may not reflect the actualcapacity of the machine and do not supersede the machinemanufacturers recommended operational limits. The user mustdetermine if testing machine capacities, allowable specimensize and maximum allowable load are appropriate for thesampl
7、e to be tested.1.5 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.
8、2. Referenced Documents2.1 ASTM Standards:2C140 Test Methods for Sampling and Testing ConcreteMasonry Units and Related UnitsC1093 Practice for Accreditation of Testing Agencies forMasonryC1314 Test Method for Compressive Strength of MasonryPrismsE4 Practices for Force Verification of Testing Machin
9、es3. Terminology3.1 Definitions:3.1.1 bearing, adjdirect contact with the specimen beingtested, as in bearing plate, bearing block, and bearing platen.3.1.2 block, nsteel piece 50 mm 2 in. thick or greaterthat provides additional load capacity in bending to platens.3.1.2.1 DiscussionBlocks may be us
10、ed to accommodatetesting specimens of various heights in a testing machine.3.1.3 composite, adjmade up of two or more pieces ormaterials.3.1.4 load frame, nall components of the testing machinethat react against forces applied to the test specimen duringtesting.3.1.5 plate, nsteel piece less than 50
11、 mm 2 in. thick.3.1.5.1 DiscussionPlates are used to accommodate testspecimens of various heights in a testing machine but do notprovide additional load capacity in bending to platens orblocks. Plates can also be used as bearing surfaces.3.1.6 platen, nthe primary bearing surfaces of the testingmach
12、ine.1This specification is under the jurisdiction of ASTM Committee C15 onManufactured Masonry Units and is the direct responsibility of SubcommitteeC15.04 on Research.Current edition approved June 1, 2011. Published June 2011. Originallyapproved in 2010. Last previous edition approved in 2010 as C1
13、716/C1716M 10.DOI: 10.1520/C1716_C1716M-11.2For 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.1*A Summary of Cha
14、nges section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.6.1 DiscussionPlaten is a general term without spe-cific properties implied. In general, the lower platen is semi-permanently fixed t
15、o the testing machine and the upper platenis semi-permanently fixed to a hemispherical thrust bearing.3.1.7 spacer, nplates, blocks, or equipment and fixturesspecific to a testing machine, used to adjust the position ofbearing surfaces to accommodate test specimens.NOTE 1Plates, blocks or platens us
16、ed in bearing must be hardened.Spacers do not have to be hardened. Blocks are structural while plates arenot.4. Testing Machine Requirements4.1 Machine Loading Requirements:4.1.1 The testing machine must be power operated andapply the load continuously, rather than intermittently, andwithout shock.4
17、.1.2 The machine must be capable of maintaining specificloading rates required by the test. Variations in the loading rateover the elastic portion of the test shall not exceed 620 % ofthe set loading rate.4.1.3 The testing machine must be capable of a minimum of50 mm 2 in. of continuous travel or di
18、splacement to accom-modate positioning and testing of a specimen.4.2 Gauges and DisplaysGauges and displays indicatingloads shall meet the requirements of Practices E4, except in nocase shall the verified force range include forces less than 100times the resolution of the force indicator.4.3 Accurac
19、yThe accuracy and calibration of the testingmachine shall meet the requirements of Practices E4, exceptthe testing machine shall be calibrated at the frequencyprescribed in Practice C1093.4.4 Load Frame:4.4.1 Load frames shall have a minimum lateral stiffness of18 3 106N/m 10 3 104lb/in., and a long
20、itudinal stiffness of18 3 108N/m 10 3 106lb/in.4.4.2 Differential longitudinal strain of the load frame due toan eccentric loading shall be limited to 0.0001 mm/mm 0.0001in./in. at the maximum capacity of the machine or the ratedcapacity of the specific test setup. Eccentricity of the load shallbe c
21、onsidered as 5 % of the maximum width of the specimen.See Appendix X1 for a discussion on allowable longitudinalstrain and machine capacity.NOTE 2In testing machines with significant differences in lateralstiffness, the center of mass and center of effort shall lay on the axisperpendicular to the ax
22、is of maximum lateral stiffness. Test specimencentroid of compressive strength may not coincide with its centroid ofmass. Test specimen section aspect ratio affects measured compressivestrength but not mass.4.4.3 If the design of the load frame makes it an integral partof the support against deflect
23、ion for platens, blocks, or testingheads, the specific parts of the load frame supporting platens,blocks, or testing heads shall meet the requirements of 4.9 forflatness, finish, and materials.4.4.4 Testing machines with fixed geometry frames andadjustable geometry frames are permitted.4.5 Plates, B
24、locks, and Platens:4.5.1 Plates, blocks, and platens shall meet requirements of4.9 for flatness and surface finish. Surface treatments or platingto reduce corrosion is permitted.4.5.2 Spacer PlateA one piece steel plate, less than 50mm 2 in. in thickness and greater than 11.5 mm 0.45 in. inthickness
25、. Spacer plates shall not be used in direct contact withthe test specimen. Spacer plates provide no additional loadcapacity in bending to platens or blocks.4.5.3 Bearing PlateA one piece hardened steel plate, lessthan 50 mm 2 in. in thickness and greater than 11.5 mm 0.45in. in thickness. Bearing pl
26、ates provide a bearing surface indirect contact with a test specimen. Bearing plates provide noadditional load capacity in bending to platens or blocks.4.5.4 Spacer BlockA one piece steel plate, 50 mm 2 in.in thickness or greater. Spacer blocks shall not be used in directcontact with the test specim
27、en.4.5.5 Bearing BlockA one piece hardened steel plate, 50mm 2 in. in thickness or greater, that provides a bearingsurface in direct contact with a test specimen. Bearing blocksprovide additional load capacity in bending to platens orblocks.4.5.6 PlatenA one piece steel plate, at least 25 mm 1 in.th
28、ick when new and at least 22 mm 0.9 in. thick when inservice. Platens may be unhardened if they are not used forbearing.NOTE 3Platens 50 mm 2 in. thick or greater act as blocks andbearing capacities in bending are calculated accordingly.4.6 Spacers:4.6.1 Spacers and bearing plates are permitted. Pla
29、tes,blocks, and spacers are used to adjust the position of bearingsurfaces to accommodate test specimens.NOTE 4Plates and blocks are usually placed between the upper andlower platens to accommodate specimen size while spacers are usuallyplaced between testing heads and the frame of the testing machi
30、ne.4.6.2 Spacers excluding those provided by the testing ma-chine manufacturer must be constructed of steel.4.6.3 Non-ferrous and composite spacers, provided by thetesting machine manufacturer, used between the upper testinghead and the lower platen shall have their load capacity clearlyindicated on
31、 the spacer and shall be used with a block orbearing block between the spacer and the test specimen.NOTE 5The block may be integral to the design of a composite spacer.4.6.4 Spacers placed between the lower platen and lowerbearing block must be a minimum of 6 mm 0.25 in. wider and6 mm 0.25 in. longe
32、r than the effective bearing area of thelower platen required for the test, or the length and width of theplaten, whichever is smaller.4.6.5 Spacers used between the upper and lower platen mustmeet all requirements of 4.9 for flatness and surface finish.4.7 Hemispherical Head Design:4.7.1 The upper
33、platen or bearing surface of the testingmachine shall be supported with a hemispherical thrust bearingto allow small angular movement of the bearing surface.NOTE 6The preferred design includes a socket and ball hemisphericalsection semi-permanently or permanently attached to a single bearingblock or
34、 platen.C1716/C1716M 1124.7.2 The ball and the socket shall be designed so that thesteel in the contact area of the hemispherical bearing does notpermanently deform when loaded to the capacity of the testingmachine or the rated load of the testing head.4.7.3 The curved surfaces of the hemispherical
35、bearingsurface shall be kept clean and shall be lubricated withpetroleum-type oil such as conventional motor oil and not withgrease.NOTE 7After contacting the specimen and application of small initialload, further tilting of the spherically seated block is neither intended nordesirable. Spherical be
36、aring blocks that rotate under load may reducemeasured strengths.4.7.4 The upper bearing surface and its attachment to thespherical seat shall be such that the bearing face can be rotatedfreely at least 2 in any direction perpendicular to the axis ofloading.4.7.5 Close contact of the hemispherical b
37、earing surfaces ispreferred. Testing head designs with the surfaces not held inclose contact at all times shall have suitable alignment fixturesto assure the hemispherical bearing surfaces contact withlateral motion less than 0.75 mm 0.03 in.4.7.6 The radius of the hemispherical bearing shall notext
38、end beyond the bearing face of the upper platen or bearingblock.4.7.7 Hemispherical bearings utilizing non-integral con-struction shall be designed to withstand lateral loads up to 7 %of the maximum rated capacity of the testing head. Non-integral construction for hemispherical bearings are thosebea
39、ring heads with the convex hemispherical bearing sectionmechanically connected to the bearing block or upper platen,rather than those machined from a single piece of steel.4.7.8 If any portion of the upper platen is less than 50 mm2 in. thick, that portion shall be considered a spacer forcalculation
40、s of deflection under load.4.7.9 The bearing surface shall be designed to meet therequirements of 4.10 for deflection under load.4.8 Lower Platen Design:4.8.1 If the lower platen is the primary bearing surface, thebearing surface shall be designed to meet the requirements of4.10 for deflection under
41、 load.4.8.2 If any portion of the lower platen is less than 50 mm2 in. thick, it shall be considered a spacer for calculations ofdeflection under load.4.9 Prescriptive Design Requirements for Blocks and Plat-ens:4.9.1 The working surfaces of blocks, plates and platensshall be finished to better than
42、 RMS (root mean square) 63.Bearing surfaces shall be finished to RMS 30 or better. Top andbottom surfaces must be parallel within 60.0005 mm/mm0.0005 in./in. on plates less than 50 mm 2 in. thick and60.0010 mm/mm 0.0010 in./in. on platens and blocks 50 mm2 in. or greater in thickness.4.9.2 The lengt
43、h and width of bearing blocks, plates, andplatens shall be a minimum of 6 mm 0.25 in. larger than thelength and width of the test specimen, respectively.4.9.3 Any surface within 1.2 mm 0.05 in. of an edge isexempt from finish and flatness requirements.4.9.4 Side surfaces not intended for loading are
44、 excludedfrom finish requirements.4.9.5 Surfaces shall be flat within 60.0125 mm in 150 mm0.0005 in. in 6 in. In addition, the entire surface excludingthe edges must be flat within 60.025 mm 0.001 in. If abearing surface is rated to a maximum specimen size, theflatness tolerance applies to the rated
45、 working area and therated size must be clearly indicated on the front of the plate,block, or platen. The rated working area shall meet therequirements of 4.9.2.NOTE 8Compliance with flatness tolerances can be determined usinga suitable straight edge and feeler gauge. A 0.025-mm 0.001-in. feelergage
46、 should be a no-go gage under a 150-mm 6-in. straight edge on anyportion of the working area. A 0.075-mm 0.003-in. feeler gauge shouldbe a no-go gauge under a straight edge spanning any portion of the ratedworking area. The 0.075-mm 0.003-in. feeler gauge is slightly oversizedto allow for the accura
47、cy of straight edges over 300 mm 12 in. in length.Other suitable methods may be used.4.9.6 All surfaces used in bearing must be hardened to aminimum of 55 HRC (HB 560). Surface treatments such asplating shall not be used to comply with the surface hardnessrequirements. Plates and blocks with one bea
48、ring surface shallhave that surface clearly indicated with permanent markings.NOTE 9 It is preferred that bearing plates and bearing blocks have allworking surfaces hardened. It is recommended that bearing surfaces behardened to a depth of 1.5 mm 0.06 in. to allow for resurfacing of thebearing face.
49、4.9.7 Permanent markings designed to aid in positioning ofspecimen and spacers or to indicate rated size that aremachined shall not exceed 0.75 mm 0.03 in. wide by 1.0 mm0.04 in. deep. Permanent markings that are etched shall notexceed 2.5 mm 0.1 in. wide by 0.005 mm 0.0002 in. deep.NOTE 10Markings are allowed, but not required by this standard.Studies have shown that machined markings can affect the results of highstrength specimens.4.9.8 Surfaces with individual scratches l
