ASTM C617-98(2003)
(Practice)Standard Practice for Capping Cylindrical Concrete Specimens
Standard Practice for Capping Cylindrical Concrete Specimens
SIGNIFICANCE AND USE
This practice describes procedures for providing plane surfaces on the ends of freshly molded concrete cylinders, hardened cylinders, or drilled concrete cores when the end surfaces do not conform with the planeness and perpendicularity requirements of applicable standards. Practice C 1231 describes alternative procedures using unbonded caps or pad caps.
SCOPE
1.1 This practice covers apparatus, materials, and procedures for capping freshly molded concrete cylinders with neat cement and hardened cylinders and drilled concrete cores with high-strength gypsum plaster or sulfur mortar.
1.2 The values stated in inch-pound units are to be regarded as the standard. The SI equivalents of inch-pound units may be approximate.
1.3 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. For specific precaution statements see 4.3 and 6.2.3.1.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C 617 – 98 (Reapproved 2003)
Standard Practice for
Capping Cylindrical Concrete Specimens
This standard is issued under the fixed designation C 617; 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 (e) 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. Scope 3. Significance and Use
1.1 This practice covers apparatus, materials, and proce- 3.1 This practice describes procedures for providing plane
dures for capping freshly molded concrete cylinders with neat surfaces on the ends of freshly molded concrete cylinders,
cement and hardened cylinders and drilled concrete cores with hardened cylinders, or drilled concrete cores when the end
high-strength gypsum plaster or sulfur mortar. surfaces do not conform with the planeness and perpendicu-
1.2 The values stated in inch-pound units are to be regarded larity requirements of applicable standards. Practice C 1231
as the standard.The SI equivalents of inch-pound units may be describes alternative procedures using unbonded caps or pad
approximate. caps.
1.3 This standard does not purport to address all of the
4. Capping Equipment
safety concerns, if any, associated with its use. It is the
4.1 Capping Plates—Neat cement caps and high-strength
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- gypsum-plaster caps shall be formed against a glass plate at
least ⁄4 in. (6 mm) thick, a machined metal plate at least 0.45
bility of regulatory limitations prior to use. For specific
precaution statements see 4.3 and 6.2.3.1. in. (11 mm) thick, or a polished plate of granite or diabase at
least 3 in. (76 mm) thick. Sulfur mortar caps shall be formed
2. Referenced Documents
against similar metal or stone plates except that the recessed
2.1 ASTM Standards: area which receives molten sulfur shall not be deeper than ⁄2
C 109/C 109M Test Method for Compressive Strength of in. (12 mm). In all cases, plates shall be at least 1 in. (25 mm)
Hydraulic Cement Mortars (Using 2-in. or 50-mm Cube greater in diameter than the test specimen and the working
Specimens) surfaces shall not depart from a plane by more than 0.002 in.
C 150 Specification for Portland Cement (0.05 mm) in 6 in. (152 mm). The surface roughness of newly
C 472 Test Methods for Physical Testing of Gypsum, Gyp- finished metal plates shall not exceed that set forth in Table 4
sum Plasters and Gypsum Concrete ofAmerican National Standard B46.1, or 125 µin. (3.2 µm) for
C 595M Specification for Blended Hydraulic Cements any type of surface and direction of lay. The surface, when
C 1231 Practice for Use of Unbonded Caps in Determina- new, shall be free of gouges, grooves, or indentations beyond
tion of Compressive Strength of Hardened Concrete Cyl- those caused by the finishing operation. Metal plates that have
inders been in use shall be free of gouges, grooves, and indentations
2.2 ANSI Standard: greater than 0.010 in. (0.25 mm) deep or greater than 0.05
2 2
B46.1 Standard for Surface Texture (Surface, Roughness, in. (32 mm ) in surface area.
Waviness and Lay)
NOTE 1—A Rockwell hardness of 48 HRC is suggested for capping
plates of devices used to form sulfur mortar caps.
4.2 Alignment Devices—Suitable alignment devices, such
This practice is under the jurisdiction of ASTM Committee C09 on Concrete
andConcreteAggregatesandisthedirectresponsibilityofSubcommitteeC09.61on
as guide bars or bull’s-eye levels, shall be used in conjunction
Testing for Strength.
with capping plates to ensure that no single cap will depart
CurrenteditionapprovedAugust10,1998.PublishedDecember1998.Originally
from perpendicularity to the axis of a cylindrical specimen by
approved in 1968. Last previous edition approved in 1998 as C 617 – 98 (2003).
more than 0.5° (approximately equivalent to ⁄8 in. in 12 in.
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
(3.2 mm in 305 mm)). The same requirement is applicable to
Standards volume information, refer to the standard’s Document Summary page on
the relationship between the axis of the alignment device and
the ASTM website.
the surface of a capping plate when guide bars are used. In
Available fromAmerican Society of Mechanical Engineers, 345 E. 47th Street,
New York, NY 10017. addition, the location of each bar with respect to its plate must
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C 617 – 98 (2003)
be such that no cap will be off-centered on a test specimen by 5.1.2 Additionally, the qualification test report must include
more than ⁄16 in. (2 mm). thecompressivestrengthof2in.cubesofthematerialqualified
4.3 Melting Pots for Sulfur Mortars—Pots used for melting and of neat cement paste cubes, if used. Capping materials
sulfur mortars shall be equipped with automatic temperature conforming to these requirements is permitted to be used for
controlsandshallbemadeofmetalorlinedwithamaterialthat cylinders with strengths up to 20 percent greater than the
is nonreactive with molten sulfur. concrete tested in these qualification tests. The manufacturer
4.3.1 Caution: Meltingpotsequippedwithperipheralheat- mustrequalifylotsofmaterialmanufacturedonanannualbasis
ing will ensure against accidents during reheating of cooled or whenever there is a change in the formulation or the raw
sulfur mixture that have a crusted-over surface. When using materials. The user of the material must retain a copy of the
melting pots not so equipped, a build-up of pressure under the qualification results, and the dates of manufacture of material
hardened surface crust on subsequent reheating may be qualified and of the material currently being used. See Table 2.
avoided by use of a metal rod that contacts the bottom of the 5.1.3 The compressive strength of capping materials shall
pot and projects above the surface of the fluid sulfur mix as it be determined by testing 2 in. cubes following the procedure
cools. The rod should be of sufficient size to conduct enough described in Test Method C 109. Except for sulfur mortars,
heat to the top on reheating to melt a ring around the rod first molding procedures shall be as in Test Method C 109 unless
andthusavoidthedevelopmentofpressure.Alargemetalladle other procedures are required to eliminate large entrapped air
can be substituted for the rod. voids. See Test Methods C 472 for alternative compaction
4.3.1.1 Use sulfur melting pots in a hood to exhaust the procedures. Cure cubes in the same environment for the same
fumes to outdoors. Heating over an open flame is dangerous length of time as the material used to cap specimens.
because the flash point of sulfur is approximately 440°F 5.1.4 The strength of the capping material shall be deter-
(227°C) and the mixture can ignite due to overheating. Should mined on receipt of a new lot and at intervals not exceeding
the mixture start to burn, covering will snuff out the flame.The three months. If a given lot of the capping material fails to
pot should be recharged with fresh material after the flame has conform to the strength requirements, it shall not be used, and
been extinguished. strengthtestsofthereplacementmaterialshallbemadeweekly
until four consecutive determinations conform to specification
requirements.
5. Capping Materials
5.2 Neat Hydraulic Cement Paste:
5.1 Thestrengthofthecappingmaterialandthethicknessof
5.2.1 Make qualification tests of the neat hydraulic cement
the caps shall conform to the requirements of Table 1.
paste prior to use for capping to establish the effects of
5.1.1 If sulfur mortar, high strength gypsum plaster and
water-cementratioandageoncompressivestrengthof2in.(50
other materials except neat cement paste are to be used to test
mm) cubes.
concrete with a strength greater than 7000 psi (50 MPa), the
manufacturer or the user of the material must provide docu-
NOTE 2—The cements used generally conform to Specification C 150
mentation: Types I, II or III; however, Specification C 595 blended cements, calcium
aluminate or other hydraulic cements producing acceptable strength may
5.1.1.1 That the average strength of 15 cylinders capped
be used.
with the material is not less than 98 percent of the average
strength of 15 companion cylinders capped with neat cement
5.2.2 Mixtheneatcementpastetothedesiredconsistencyat
paste or 15 cylinders ground plane to within 0.002 in. (0.05
a water-cement ratio equal to or less than that required to
mm).
produce the required strength, generally 2 to 4 h before the
5.1.1.2 That the standard deviation of the strengths of the
paste is to be used (Note 3). Remix as necessary to maintain
capped cylinders is not greater than 1.57 times that of the
acceptable consistency (Note 4). Some retempering of the
standard deviation of the reference cylinders.
paste is acceptable if the required water-cement ratio is not
5.1.1.3 That the cap thickness requirements were met in the
exceeded. Optimum consistency is generally produced at
qualification tests, and
water-cement ratios of 0.32 to 0.36 by mass for Type I and
5.1.1.4 Of the hardening time of the caps used in the
Type II cements and 0.35 to 0.39 by mass forType III cements.
qualification tests.
NOTE 3—Freshly mixed pastes tend to bleed, shrink, and make unac-
ceptable caps. The 2 to 4 h period is generally appropriate for portland
cements.
TABLE 1 Compressive Strength and Maximum Thickness of
NOTE 4—The required consistency of the paste is determined by the
Capping Materials
appearance of the cap when it is stripped. Fluid paste results in streaks in
Cylinder Maximum Maximum
the cap. Stiff paste results in thick caps.
Compressive Average Thickness
Strength psi Minimum Strength of Capping Thickness Any Part
5.3 High-Strength Gypsum Cement Paste:
(MPa) Material of Cap of Cap
5.3.1 No fillers or extenders may be added to neat high-
1 5
500 to 7000 5000 psi (35 MPa) or cylinder ⁄4 in. ⁄16 in.
strength gypsum cement paste subsequent to the manufacture
psi (3.5 to strength whichever is greater (6 mm) (8 mm)
of the cement. (Note 5) Qualification tests shall be made to
50 MPa)
1 3
greater than Compressive strength not less ⁄8 in. ⁄16 in. determine the effects of water-cement ratio and age on com-
7000 psi than (3 mm) (5 mm)
pressive strength of 2 in. (50 mm) cubes. Retarders may be
(50 MPa) cylinder strength, except as
used to extend working time, but their effects on required
provided in 5.1.1
water-cement ratio and strength must be determined. (Note 6)
C 617 – 98 (2003)
TABLE 2 Sample Report of Qualification of a Capping Material
NOTE—Manufacturer: Testing Supplies Co.
Capping Material: Super Strong AAA-Sulfor mortar
Lot: 12a45 Date Tested: 11/3/98
Signed by:______________________________ (testing agency and responsible official)
Capping
Item Material Control Cylinders Ratio Criteria Pass/Fail
Concrete Cylinder Test Data
Type of capping material Sulfur Ground
Average Concrete Strength, psi [MPa] 11 061 (76.2) 11 008 (75.9) 1.005 >0.98 Xc Pass
Standard Deviation, psi [MPa] 376 (2.59) 250 (1.72) 1.504 #1.57 C Pass
Number of cylinders tested 15 15
Cap age when cylinders tested 7 days na
Capping Material Test Data
Average cap thickness, in. [mm] 0.11 (2.8) na
Compressive strength of 2 in. [50 mm] cubes, psi (MPa) 12 195 (91)
Cube age when tested. 7 days
A
Maximum concrete strength qualified, psi (MPa) 1.2 Av. Str = 13 273 (91.5)
A
Nominally a specified strength of 11 000 psi (75 MPa) and perhaps somewhat higher.
NOTE 5—Low-strength molding plaster, plaster of paris, or mixtures of
5.4.2 Determination of Compressive Strength—Prepare test
plaster of paris and portland cement are unsuitable for capping.
specimens using a cube mold and base plate conforming to the
NOTE 6—The water-gypsum cement ratio should be between 0.26 and
requirements of Test Method C 109 and a metal cover plate
0.30. Use of low water-cement ratios and vigorous mixing will usually
conforming in principle to the design shown in Fig. 1 (Note 7).
permit development of 5000 psi (35 MPa) at ages of 1 or 2 h. Higher
Bring the various parts of the apparatus to a temperature of 68
water-gypsum cement ratios extend working time, but reduce strength.
to 86°F (20 to 30°C), lightly coat the surfaces that will be in
5.3.2 Mix the neat gypsum cement paste at the desired
contact with the sulfur mortar with mineral oil, and assemble
water-cement ratio and use it promptly since it sets rapidly.
near the melting pot. Bring the temperature of the molten-
5.4 Sulfur Mortar:
sulfur mortar in the pot within a range of 265 to 290°F (129 to
5.4.1 Proprietary or laboratory prepared sulfur mortars are
143°C), stir thoroughly, and begin casting cubes. Using a ladle,
permitted if allowed to harden a minimum of 2 h before testing
or other suitable pouring device, quickly fill each of the three
concrete with strength less than 5000 psi (35 MPa). For
compartments until the molten material reaches the top of the
concrete strengths of 5000 psi or greater, sulfur mortar caps
must be allowed to harden at least 16 h before testing, unless filling hole.Allow sufficient time for maximum shrinkage, due
a shorter time has been shown to be suitable as specified in to cooling, and solidification to occur (approximately 15 min)
5.1.1. and refill each hole with molten material (Note 8). After
FIG. 1 Sketch of Cover Plate for 2-in. (50-mm) Cube Mold
C 617 – 98 (2003)
solidification is complete, remove the cubes from the mold cylinder shall not exceed ⁄8 in. (3 mm) (Note 11). If the end
without breaking off the knob formed by the filling hole in the exceeds this limit, the end of the cylinder shall be cut, lapped
cover plate. Remove oil, sharp edges, and fins from the cubes
or ground prior to capping.
and check the planeness of the bearing surfaces in the manner
NOTE 11—This provision is to control the difference between the
described in Test Method C 109. After storage at room tem-
thickest and thinnest parts of a cap. The distance may be checked using a
perature to the desired age, but not less than 2 h, test cubes in
square with one blade touching the cylinder parallel to the cylinder axis
compression following the procedure described inTest Method
and the other blade touching the highest point on the end of the cylinder.
C 109, and calculate the compressive strength.
The distance
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.