ASTM C1716/C1716M-14
(Specification)Standard Specification for Compression Testing Machine Requirements for Concrete Masonry Units, Related Units, and Prisms
Standard Specification for Compression Testing Machine Requirements for Concrete Masonry Units, Related Units, and Prisms
SCOPE
1.1 This specification provides minimum design standards for testing machines used to measure the compressive strength of concrete masonry units, related units, and masonry prisms covered under Test Methods C140 and C1314.
1.2 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this standard.
1.3 This specification shall be used to determine the maximum allowable specimen size and the maximum allowable load limits on a specific specimen for any test machine. These limits are based on deflection of the bearing surfaces and the machine load frame. These limits may not reflect the actual capacity of the machine and do not supersede the machine manufacturer’s recommended operational limits. The user must determine if testing machine capacities, allowable specimen size and maximum allowable load are appropriate for the sample to be tested.
1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation:C1716/C1716M −14
StandardSpecification for
Compression Testing Machine Requirements for Concrete
Masonry Units, Related Units, and Prisms
This standard is issued under the fixed designation C1716/C1716M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year 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. Scope* 2. Referenced Documents
1.1 This specification provides minimum design standards
2.1 ASTM Standards:
for testing machines used to measure the compressive strength C140Test Methods for Sampling and Testing Concrete
of concrete masonry units, related units, and masonry prisms Masonry Units and Related Units
covered under Test Methods C140 and C1314. C1093Practice for Accreditation of Testing Agencies for
Masonry
1.2 The text of this standard references notes and footnotes
C1314Test Method for Compressive Strength of Masonry
which provide explanatory material.These notes and footnotes
Prisms
(excluding those in tables and figures) shall not be considered
E4Practices for Force Verification of Testing Machines
as requirements of this standard.
1.3 This specification shall be used to determine the maxi-
3. Terminology
mum allowable specimen size and the maximum allowable
3.1 Definitions:
load limits on a specific specimen for any test machine. These
3.1.1 bearing, adj—direct contact with the specimen being
limits are based on deflection of the bearing surfaces and the
tested, as in bearing plate, bearing block, and bearing platen.
machine load frame. These limits may not reflect the actual
3.1.2 block, n—steel piece 50 mm [2 in.] thick or greater
capacity of the machine and do not supersede the machine
manufacturer’srecommendedoperationallimits.Theusermust that provides additional load capacity in bending to platens.
determine if testing machine capacities, allowable specimen 3.1.2.1 Discussion—Blocks may be used to accommodate
size and maximum allowable load are appropriate for the testing specimens of various heights in a testing machine.
sample to be tested.
3.1.3 composite, adj—made up of two or more pieces or
materials.
1.4 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. The values stated in
3.1.4 load frame, n—all components of the testing machine
each system may not be exact equivalents; therefore, each
that react against forces applied to the test specimen during
system shall be used independently of the other. Combining
testing.
values from the two systems may result in non-conformance
3.1.5 plate, n—steel piece less than 50 mm [2 in.] thick.
with the standard.
3.1.5.1 Discussion—Plates are used to accommodate test
1.5 This standard does not purport to address all of the
specimens of various heights in a testing machine but do not
safety concerns, if any, associated with its use. It is the
provide additional load capacity in bending to platens or
responsibility of the user of this standard to establish appro-
blocks. Plates can also be used as bearing surfaces.
priate safety and health practices and determine the applica-
3.1.6 platen, n—the primary bearing surfaces of the testing
bility of regulatory limitations prior to use.
machine.
This specification is under the jurisdiction of ASTM Committee C15 on
Manufactured Masonry Units and is the direct responsibility of Subcommittee
C15.04 on Research. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Dec. 1, 2014. Published December 2014. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2010. Last previous edition approved in 2012 as C1716/C1716M–12. Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/C1716_C1716M-14. the ASTM website.
*A Summary of Changes 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
C1716/C1716M−14
3.1.6.1 Discussion—Platen is a general term without spe- 4.5.1 Plates, blocks, and platens shall meet requirements of
cific properties implied. In general, the lower platen is semi- 4.9forflatnessandsurfacefinish.Surfacetreatmentsorplating
permanently fixed to the testing machine and the upper platen to reduce corrosion is permitted.
is semi-permanently fixed to a hemispherical thrust bearing. 4.5.2 Spacer Plate—A one piece steel plate, less than 50
mm [2 in.] in thickness and greater than 11.5 mm [0.45 in.] in
3.1.7 spacer, n—plates, blocks, or equipment and fixtures
thickness.Spacerplatesshallnotbeusedindirectcontactwith
specific to a testing machine, used to adjust the position of
the test specimen. Spacer plates provide no additional load
bearing surfaces to accommodate test specimens.
capacity in bending to platens or blocks.
NOTE 1—Plates, blocks or platens used in bearing must be hardened.
4.5.3 Bearing Plate—Aone piece hardened steel plate, less
Spacers do not have to be hardened. Blocks are structural while plates are
than50mm[2in.]inthicknessandgreaterthan11.5mm[0.45
not.
in.] in thickness. Bearing plates provide a bearing surface in
direct contact with a test specimen. Bearing plates provide no
4. Testing Machine Requirements
additional load capacity in bending to platens or blocks.
4.1 Machine Loading Requirements:
4.5.4 Spacer Block—Aone piece steel plate, 50 mm [2 in.]
4.1.1 The testing machine must be power operated and
inthicknessorgreater.Spacerblocksshallnotbeusedindirect
apply the load continuously, rather than intermittently, and
contact with the test specimen.
without shock.
4.5.5 Bearing Block—A one piece hardened steel plate, 50
4.1.2 The machine must be capable of maintaining specific
mm [2 in.] in thickness or greater, that provides a bearing
loading rates required by the test.Variations in the loading rate
surface in direct contact with a test specimen. Bearing blocks
over the elastic portion of the test shall not exceed 620% of
provide additional load capacity in bending to platens or
the set loading rate.
blocks.
4.1.3 Thetestingmachinemustbecapableofaminimumof
4.5.6 Platen—Aone piece steel plate, at least 25 mm [1 in.]
50 mm [2 in.] of continuous travel or displacement to accom-
thick when new and at least 22 mm [0.9 in.] thick when in
modate positioning and testing of a specimen.
service. Platens may be unhardened if they are not used for
bearing.
4.2 Gauges and Displays—Gauges and displays indicating
loads shall meet the requirements of Practices E4, except in no
NOTE 3—Platens 50 mm [2 in.] thick or greater act as blocks and
case shall the verified force range include forces less than 100
bearing capacities in bending are calculated accordingly.
times the resolution of the force indicator.
4.6 Spacers:
4.3 Accuracy—The accuracy and calibration of the testing
4.6.1 Spacers and bearing plates are permitted. Plates,
machine shall meet the requirements of Practices E4, except blocks, and spacers are used to adjust the position of bearing
the testing machine shall be calibrated at the frequency
surfaces to accommodate test specimens.
prescribed in Practice C1093.
NOTE 4—Plates and blocks are usually placed between the upper and
lower platens to accommodate specimen size while spacers are usually
4.4 Load Frame:
placed between testing heads and the frame of the testing machine.
4.4.1 Load frames shall have a minimum lateral stiffness of
6 4
18×10 N/m [10 × 10 lb/in.], and a longitudinal stiffness of 4.6.2 Spacers excluding those provided by the testing ma-
8 6
18×10 N/m [10 × 10 lb/in.]. chine manufacturer must be constructed of steel.
4.4.2 Differentiallongitudinalstrainoftheloadframedueto
4.6.3 Non-ferrous and composite spacers, provided by the
aneccentricloadingshallbelimitedto0.0001mm/mm[0.0001 testing machine manufacturer, used between the upper testing
in./in.] at the maximum capacity of the machine or the rated
headandthelowerplatenshallhavetheirloadcapacityclearly
capacityofthespecifictestsetup.Eccentricityoftheloadshall indicated on the spacer and shall be used with a block or
be considered as 5% of the maximum width of the specimen. bearing block between the spacer and the test specimen.
See Appendix X1 for a discussion on allowable longitudinal
NOTE5—Theblockmaybeintegraltothedesignofacompositespacer.
strain and machine capacity.
4.6.4 Spacers placed between the lower platen and lower
NOTE 2—In testing machines with significant differences in lateral
bearingblockmustbeaminimumof6mm[0.25in.]widerand
stiffness, the center of mass and center of effort shall lie on the axis
6 mm [0.25 in.] longer than the effective bearing area of the
perpendiculartotheaxisofmaximumlateralstiffness(seeFig.A1.3).Test
lowerplatenrequiredforthetest,orthelengthandwidthofthe
specimen centroid of compressive strength may not coincide with its
centroid of mass. Test specimen section aspect ratio affects measured platen, whichever is smaller.
compressive strength but not mass.
4.6.5 Spacersusedbetweentheupperandlowerplatenmust
meet all requirements of 4.9 for flatness and surface finish.
4.4.3 Ifthedesignoftheloadframemakesitanintegralpart
of the support against deflection for platens, blocks, or testing
4.7 Hemispherical Head Design:
heads, the specific parts of the load frame supporting platens,
4.7.1 The upper platen or bearing surface of the testing
blocks, or testing heads shall meet the requirements of 4.9 for
machineshallbesupportedwithahemisphericalthrustbearing
flatness, finish, and materials.
to allow small angular movement of the bearing surface.
4.4.4 Testing machines with fixed geometry frames and
NOTE6—Thepreferreddesignincludesasocketandballhemispherical
adjustable geometry frames are permitted.
section semi-permanently or permanently attached to a single bearing
4.5 Plates, Blocks, and Platens: block or platen.
C1716/C1716M−14
4.7.2 The ball and the socket shall be designed so that the 4.9.3 Any surface within 1.2 mm [0.05 in.] of an edge is
steel in the contact area of the hemispherical bearing does not exempt from finish and flatness requirements.
permanently deform when loaded to the capacity of the testing 4.9.4 Side surfaces not intended for loading are excluded
machine or the rated load of the testing head. from finish requirements.
4.7.3 The curved surfaces of the hemispherical bearing 4.9.5 Surfaces shall be flat within 60.0125 mm in 150 mm
[0.0005 in. in 6 in.]. In addition, the entire surface excluding
surface shall be kept clean and shall be lubricated with
petroleum-typeoilsuchasconventionalmotoroilandnotwith the edges must be flat within 60.025 mm [0.001 in.]. If a
grease. bearing surface is rated to a maximum specimen size, the
flatness tolerance applies to the rated working area and the
NOTE 7—After contacting the specimen and application of small initial
rated size must be clearly indicated on the front of the plate,
load, further tilting of the spherically seated block is neither intended nor
block, or platen. The rated working area shall meet the
desirable. Spherical bearing blocks that rotate under load may reduce
measured strengths. requirements of 4.9.2.
4.7.4 The upper bearing surface and its attachment to the
NOTE 8—Compliance with flatness tolerances can be determined using
a suitable straight edge and feeler gauge. A 0.025-mm [0.001-in.] feeler
spherical seat shall be such that the bearing face can be rotated
gage should be a no-go gage under a 150-mm [6-in.] straight edge on any
freely at least 2° in any direction perpendicular to the axis of
portion of the working area.A0.075-mm [0.003-in.] feeler gauge should
loading.
be a no-go gauge under a straight edge spanning any portion of the rated
4.7.5 Close contact of the hemispherical bearing surfaces is
workingarea.The0.075-mm[0.003-in.]feelergaugeisslightlyoversized
preferred. Testing head designs with the surfaces not held in toallowfortheaccuracyofstraightedgesover300mm[12in.]inlength.
Other suitable methods may be used.
close contact at all times shall have suitable alignment fixtures
to assure the hemispherical bearing surfaces contact with
4.9.6 All surfaces used in bearing must be hardened to a
lateral motion less than 0.75 mm [0.03 in.].
minimum of 55 HRC (HB 560). Surface treatments such as
4.7.6 The radius of the hemispherical bearing shall not
plating shall not be used to comply with the surface hardness
extend beyond the bearing face of the upper platen or bearing requirements. Plates and blocks with one bearing surface shall
block.
have that surface clearly indicated with permanent markings.
4.7.7 Hemispherical bearings utilizing non-integral con-
NOTE 9— It is preferred that bearing plates and bearing blocks have all
struction shall be designed to withstand lateral loads up to 7%
working surfaces hardened. It is recommended that bearing surfaces be
of the maximum rated capacity of the testing head. Non-
hardened to a depth of 1.5 mm [0.06 in.] to allow for resurfacing of the
bearing face.
integral construction for hemispherical bearings are those
bearing heads with the convex hemispherical bearing section
4.9.7 Permanent markings designed to aid in positioning of
mechanically connected to the bearing block or upper platen,
specimen and spacers or to indicate rated size that are
rather than those machined from a single piece of steel.
machined shall not exceed 0.75 mm [0.03 in.] wide by 1.0 mm
4.7.8 If any portion of the upper platen is less than 50 mm
[0.04 in.] deep. Permanent markings that are etched shall not
[2 in.] thick, that portion shall be considered a spacer for
exceed 2.5 mm [0.1 in.] wide by 0.005 mm [0.0002 in.] deep.
calculations of deflection under load. In a hemispherical head
NOTE 10—Markings are allowed, but not required by this standard.
utilizing non-integral construction, the hemispherical bearing
Studies have shown that machined markings can affect the results of high
portion shall be exempt from this requirement.
strength specimens.
4.7.9 The bearing surface shall be designed to meet the
4.9.8 Surfaces with individual scratches larger than 0.25
requirements of 4.10 for deflection under load.
mm [0.010 in.] wide by 50 mm [2 in.] long, and individual
2 2
4.8 Lower Platen Design: dents with area exceeding 30 mm [0.05 in ] (approximately 6
4.8.1 If the lower platen is the primary bearing surface, the mm [0.25 in] in diameter), and depth exceeding 0.12 mm
bearing surface shall be designed to meet the requirements of [0.005 in.] shall not be used as bearing surfaces. Scratches and
dents outside the bearing area of 4.9.2 are excluded.
4.10 for deflection under
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C1716/C1716M − 12 C1716/C1716M − 14
Standard Specification for
Compression Testing Machine Requirements for Concrete
Masonry Units, Related Units, and Prisms
This standard is issued under the fixed designation C1716/C1716M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year 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. Scope*
1.1 This specification provides minimum design standards for testing machines used to measure the compressive strength of
concrete masonry units, related units, and masonry prisms covered under Test Methods C140 and C1314.
1.2 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes
(excluding those in tables and figures) shall not be considered as requirements of this standard.
1.3 This specification shall be used to determine the maximum allowable specimen size and the maximum allowable load limits
on a specific specimen for any test machine. These limits are based on deflection of the bearing surfaces and the machine load
frame. These limits may not reflect the actual capacity of the machine and do not supersede the machine manufacturer’s
recommended operational limits. The user must determine if testing machine capacities, allowable specimen size and maximum
allowable load are appropriate for the sample to be tested.
1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the
two systems may result in non-conformance with the standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
C140 Test Methods for Sampling and Testing Concrete Masonry Units and Related Units
C1093 Practice for Accreditation of Testing Agencies for Masonry
C1314 Test Method for Compressive Strength of Masonry Prisms
E4 Practices for Force Verification of Testing Machines
3. Terminology
3.1 Definitions:
3.1.1 bearing, adj—direct contact with the specimen being tested, as in bearing plate, bearing block, and bearing platen.
3.1.2 block, n—steel piece 50 mm [2 in.] thick or greater that provides additional load capacity in bending to platens.
This specification is under the jurisdiction of ASTM Committee C15 on Manufactured Masonry Units and is the direct responsibility of Subcommittee C15.04 on
Research.
Current edition approved Dec. 1, 2012Dec. 1, 2014. Published December 2012December 2014. Originally approved in 2010. Last previous edition approved in 20112012
as C1716/C1716M – 11.C1716/C1716M – 12. DOI: 10.1520/C1716_C1716M-12.10.1520/C1716_C1716M-14.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3.1.2.1 Discussion—
Blocks may be used to accommodate testing specimens of various heights in a testing machine.
3.1.3 composite, adj—made up of two or more pieces or materials.
3.1.4 load frame, n—all components of the testing machine that react against forces applied to the test specimen during testing.
*A Summary of Changes 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
C1716/C1716M − 14
3.1.5 plate, n—steel piece less than 50 mm [2 in.] thick.
3.1.5.1 Discussion—
Plates are used to accommodate test specimens of various heights in a testing machine but do not provide additional load capacity
in bending to platens or blocks. Plates can also be used as bearing surfaces.
3.1.6 platen, n—the primary bearing surfaces of the testing machine.
3.1.6.1 Discussion—
Platen is a general term without specific properties implied. In general, the lower platen is semi-permanently fixed to the testing
machine and the upper platen is semi-permanently fixed to a hemispherical thrust bearing.
3.1.7 spacer, n—plates, blocks, or equipment and fixtures specific to a testing machine, used to adjust the position of bearing
surfaces to accommodate test specimens.
NOTE 1—Plates, blocks or platens used in bearing must be hardened. Spacers do not have to be hardened. Blocks are structural while plates are not.
4. Testing Machine Requirements
4.1 Machine Loading Requirements : Requirements:
4.1.1 The testing machine must be power operated and apply the load continuously, rather than intermittently, and without
shock.
4.1.2 The machine must be capable of maintaining specific loading rates required by the test. Variations in the loading rate over
the elastic portion of the test shall not exceed 620 % of the set loading rate.
4.1.3 The testing machine must be capable of a minimum of 50 mm [2 in.] of continuous travel or displacement to accommodate
positioning and testing of a specimen.
4.2 Gauges and Displays—Gauges and displays indicating loads shall meet the requirements of Practices E4, except in no case
shall the verified force range include forces less than 100 times the resolution of the force indicator.
4.3 Accuracy—The accuracy and calibration of the testing machine shall meet the requirements of Practices E4, except the
testing machine shall be calibrated at the frequency prescribed in Practice C1093.
4.4 Load Frame:
6 4
4.4.1 Load frames shall have a minimum lateral stiffness of 18 × 10 N/m [10 × 10 lb/in.], and a longitudinal stiffness of 18
8 6
× 10 N/m [10 × 10 lb/in.].
4.4.2 Differential longitudinal strain of the load frame due to an eccentric loading shall be limited to 0.0001 mm/mm [0.0001
in./in.] at the maximum capacity of the machine or the rated capacity of the specific test setup. Eccentricity of the load shall be
considered as 5 % of the maximum width of the specimen. See Appendix X1 for a discussion on allowable longitudinal strain and
machine capacity.
NOTE 2—In testing machines with significant differences in lateral stiffness, the center of mass and center of effort shall lie on the axis perpendicular
to the axis of maximum lateral stiffness (see Fig. A1.3). Test specimen centroid of compressive strength may not coincide with its centroid of mass. Test
specimen section aspect ratio affects measured compressive strength but not mass.
4.4.3 If the design of the load frame makes it an integral part of the support against deflection for platens, blocks, or testing
heads, the specific parts of the load frame supporting platens, blocks, or testing heads shall meet the requirements of 4.9 for
flatness, finish, and materials.
4.4.4 Testing machines with fixed geometry frames and adjustable geometry frames are permitted.
4.5 Plates, Blocks, and Platens:
4.5.1 Plates, blocks, and platens shall meet requirements of 4.9 for flatness and surface finish. Surface treatments or plating to
reduce corrosion is permitted.
4.5.2 Spacer Plate—A one piece steel plate, less than 50 mm [2 in.] in thickness and greater than 11.5 mm [0.45 in.] in thickness.
Spacer plates shall not be used in direct contact with the test specimen. Spacer plates provide no additional load capacity in bending
to platens or blocks.
4.5.3 Bearing Plate—A one piece hardened steel plate, less than 50 mm [2 in.] in thickness and greater than 11.5 mm [0.45 in.]
in thickness. Bearing plates provide a bearing surface in direct contact with a test specimen. Bearing plates provide no additional
load capacity in bending to platens or blocks.
4.5.4 Spacer Block—A one piece steel plate, 50 mm [2 in.] in thickness or greater. Spacer blocks shall not be used in direct
contact with the test specimen.
4.5.5 Bearing Block—A one piece hardened steel plate, 50 mm [2 in.] in thickness or greater, that provides a bearing surface
in direct contact with a test specimen. Bearing blocks provide additional load capacity in bending to platens or blocks.
C1716/C1716M − 14
4.5.6 Platen—A one piece steel plate, at least 25 mm [1 in.] thick when new and at least 22 mm [0.9 in.] thick when in service.
Platens may be unhardened if they are not used for bearing.
NOTE 3—Platens 50 mm [2 in.] thick or greater act as blocks and bearing capacities in bending are calculated accordingly.
4.6 Spacers:
4.6.1 Spacers and bearing plates are permitted. Plates, blocks, and spacers are used to adjust the position of bearing surfaces
to accommodate test specimens.
NOTE 4—Plates and blocks are usually placed between the upper and lower platens to accommodate specimen size while spacers are usually placed
between testing heads and the frame of the testing machine.
4.6.2 Spacers excluding those provided by the testing machine manufacturer must be constructed of steel.
4.6.3 Non-ferrous and composite spacers, provided by the testing machine manufacturer, used between the upper testing head
and the lower platen shall have their load capacity clearly indicated on the spacer and shall be used with a block or bearing block
between the spacer and the test specimen.
NOTE 5—The block may be integral to the design of a composite spacer.
4.6.4 Spacers placed between the lower platen and lower bearing block must be a minimum of 6 mm [0.25 in.] wider and 6 mm
[0.25 in.] longer than the effective bearing area of the lower platen required for the test, or the length and width of the platen,
whichever is smaller.
4.6.5 Spacers used between the upper and lower platen must meet all requirements of 4.9 for flatness and surface finish.
4.7 Hemispherical Head Design:
4.7.1 The upper platen or bearing surface of the testing machine shall be supported with a hemispherical thrust bearing to allow
small angular movement of the bearing surface.
NOTE 6—The preferred design includes a socket and ball hemispherical section semi-permanently or permanently attached to a single bearing block
or platen.
4.7.2 The ball and the socket shall be designed so that the steel in the contact area of the hemispherical bearing does not
permanently deform when loaded to the capacity of the testing machine or the rated load of the testing head.
4.7.3 The curved surfaces of the hemispherical bearing surface shall be kept clean and shall be lubricated with petroleum-type
oil such as conventional motor oil and not with grease.
NOTE 7—After contacting the specimen and application of small initial load, further tilting of the spherically seated block is neither intended nor
desirable. Spherical bearing blocks that rotate under load may reduce measured strengths.
4.7.4 The upper bearing surface and its attachment to the spherical seat shall be such that the bearing face can be rotated freely
at least 2° in any direction perpendicular to the axis of loading.
4.7.5 Close contact of the hemispherical bearing surfaces is preferred. Testing head designs with the surfaces not held in close
contact at all times shall have suitable alignment fixtures to assure the hemispherical bearing surfaces contact with lateral motion
less than 0.75 mm [0.03 in.].
4.7.6 The radius of the hemispherical bearing shall not extend beyond the bearing face of the upper platen or bearing block.
4.7.7 Hemispherical bearings utilizing non-integral construction 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 those bearing heads with the
convex hemispherical bearing section mechanically 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 mm [2 in.] thick, that portion shall be considered a spacer for calculations
of deflection under load. In a hemispherical head utilizing non-integral construction, the hemispherical bearing portion shall be
exempt from this requirement.
4.7.9 The bearing surface shall be designed to meet the requirements of 4.10 for deflection under load.
4.8 Lower Platen Design:
4.8.1 If the lower platen is the primary bearing surface, the bearing surface shall be designed to meet the requirements of 4.10
for deflection under load.
4.8.2 If any portion of the lower platen is less than 50 mm [2 in.] thick, it shall be considered a spacer for calculations of
deflection under load.
4.9 Prescriptive Design Requirements for Blocks and Platens:
4.9.1 The working surfaces of blocks, plates and platens shall be finished to better than RMS (root mean square) 63. Bearing
surfaces shall be finished to RMS 30 or better. Top and bottom surfaces must be parallel within 60.0005 mm/mm [0.0005 in./in.]
on plates less than 50 mm [2 in.] thick and 60.0010 mm/mm [0.0010 in. ⁄in.] on platens and blocks 50 mm [2 in.] or greater in
thickness.
4.9.2 The length and width of bearing blocks, plates, and platens shall be a minimum of 6 mm [0.25 in.] larger than the length
and width of the test specimen, respectively.
C1716/C1716M − 14
4.9.3 Any surface within 1.2 mm [0.05 in.] of an edge is exempt from finish and flatness requirements.
4.9.4 Side surfaces not intended for loading are excluded from finish requirements.
4.9.5 Surfaces shall be flat within 60.0125 mm in 150 mm [0.0005 in. in 6 in.]. In addition, the entire surface excluding the
edges must be flat within 60.025 mm [0.001 in.]. If a bearing surface is rated to a maximum specimen size, the flatness tolerance
applies to the rated working area and the rated size must be clearly indicated on the front of the plate, block, or platen. The rated
working area shall meet the requirements of 4.9.2.
NOTE 8—Compliance with flatness tolerances can be determined using a suitable straight edge and feeler gauge. A 0.025-mm [0.001-in.] feeler gage
should be a no-go gage under a 150-mm [6-in.] straight edge on any portion of the working area. A 0.075-mm [0.003-in.] feeler gauge should be a no-go
gauge under a straight edge spanning any portion of the rated working area. The 0.075-mm [0.003-in.] feeler gauge is slight
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