ASTM C157/C157M-08(2014)e1
(Test Method)Standard Test Method for Length Change of Hardened Hydraulic-Cement Mortar and Concrete
Standard Test Method for Length Change of Hardened Hydraulic-Cement Mortar and Concrete
SIGNIFICANCE AND USE
4.1 Measurement of length change permits assessment of the potential for volumetric expansion or contraction of mortar or concrete due to various causes other than applied force or temperature change. This test method is particularly useful for comparative evaluation of this potential in different hydraulic-cement mortar or concrete mixtures.
4.2 This test method provides useful information for experimental purposes or for products that require testing under nonstandard mixing, placing, handling, or curing conditions, such as high product workability or different demolding times. Standard conditions are described in 5.4.1.
4.3 If conditions for mixing, curing, sampling, and storage other than specified in this test method are required, they shall be reported but are not to be considered as standard conditions of this test method. Nonstandard conditions and the reasons for departure from standard conditions shall be reported clearly and prominently with comparator values.
SCOPE
1.1 This test method covers the determination of the length changes that are produced by causes other than externally applied forces and temperature changes in hardened hydraulic-cement mortar and concrete specimens made in the laboratory and exposed to controlled conditions of temperature and moisture.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. An exception is with regard to sieve sizes and nominal size of aggregate, in which the SI values are the standard as stated in Specification E11. Within the text, the SI units are shown in brackets. 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.
1.3 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.
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´1
Designation: C157/C157M − 08 (Reapproved 2014)
Standard Test Method for
Length Change of Hardened Hydraulic-Cement Mortar and
Concrete
This standard is issued under the fixed designation C157/C157M; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
ε NOTE—Editorial corrections were made in November 2014.
1. Scope* C192/C192M Practice for Making and Curing Concrete Test
Specimens in the Laboratory
1.1 This test method covers the determination of the length
C305 Practice for Mechanical Mixing of Hydraulic Cement
changes that are produced by causes other than externally
Pastes and Mortars of Plastic Consistency
applied forces and temperature changes in hardened hydraulic-
C490 Practice for Use ofApparatus for the Determination of
cement mortar and concrete specimens made in the laboratory
Length Change of Hardened Cement Paste, Mortar, and
and exposed to controlled conditions of temperature and
Concrete
moisture.
C511 Specification for Mixing Rooms, Moist Cabinets,
1.2 The values stated in either SI units or inch-pound units
Moist Rooms, and Water Storage Tanks Used in the
are to be regarded separately as standard.An exception is with
Testing of Hydraulic Cements and Concretes
regard to sieve sizes and nominal size of aggregate, in which
C596 Test Method for Drying Shrinkage of Mortar Contain-
the SI values are the standard as stated in Specification E11.
ing Hydraulic Cement
Within the text, the SI units are shown in brackets. The values
C1437 Test Method for Flow of Hydraulic Cement Mortar
stated in each system may not be exact equivalents; therefore,
E11 Specification for Woven Wire Test Sieve Cloth and Test
each system shall be used independently of the other. Combin-
Sieves
ing values from the two systems may result in non-
E337 Test Method for Measuring Humidity with a Psy-
conformance with the standard.
chrometer (the Measurement of Wet- and Dry-Bulb Tem-
1.3 This standard does not purport to address all of the
peratures)
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3. Terminology
priate safety and health practices and determine the applica-
3.1 Definitions—The terms used in this test method are
bility of regulatory limitations prior to use.
defined in Terminology C125.
3.2 Definitions of Terms Specific to This Standard:
2. Referenced Documents
2 3.2.1 length change, n—an increase or decrease in the
2.1 ASTM Standards:
lengthofatestspecimenthathasbeencausedtochangebyany
C125 Terminology Relating to Concrete and Concrete Ag-
factor other than externally applied forces and temperature
gregates
changes.
C143/C143M Test Method for Slump of Hydraulic-Cement
Concrete
4. Significance and Use
C172 Practice for Sampling Freshly Mixed Concrete
4.1 Measurement of length change permits assessment of
the potential for volumetric expansion or contraction of mortar
This test method is under the jurisdiction of ASTM Committee C09 on
or concrete due to various causes other than applied force or
Concrete and ConcreteAggregates and is the direct responsibility of Subcommittee
C09.68 on Volume Change. temperature change. This test method is particularly useful for
Current edition approved Oct. 1, 2014. Published November 2014. Originally
comparative evaluation of this potential in different hydraulic-
ε1
approved in 1940. Last previous edition approved in 2008 as C157/C157M – 08 .
cement mortar or concrete mixtures.
DOI: 10.1520/C0157_C0157M-08R14E01.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4.2 This test method provides useful information for experi-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
mental purposes or for products that require testing under
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. nonstandard mixing, placing, handling, or curing conditions,
*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
´1
C157/C157M − 08 (2014)
FIG. 1 Atmometer
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C157/C157M − 08 (2014)
such as high product workability or different demolding times. 5.5.1 Mounting—Fig. 2 shows a suggested arrangement for
Standard conditions are described in 5.4.1. operating the atmometer. Punch a central hole ⁄2 in. [13 mm]
in diameter in a filter paper, place it on the atmometer, and
4.3 If conditions for mixing, curing, sampling, and storage
secure it in place while dry, by turning the torque handle only,
other than specified in this test method are required, they shall
until it just starts to slip. Mount the atmometer on a stand with
be reported but are not to be considered as standard conditions
the filter paper in a horizontal position. Mount a 100-mL glass
of this test method. Nonstandard conditions and the reasons for
graduate so that the 100-mL mark is from 1 to 3 in. [25 to 75
departure from standard conditions shall be reported clearly
mm] below the level of the filter paper. Stopper the graduate so
and prominently with comparator values.
that entrance is provided for two short glass tubes not extend-
ing to the water level and one long tube extending to the
5. Apparatus
bottom of the graduate. Connect the glass tubing leading from
5.1 Molds and Length Comparator—The molds for casting
the bottom of the graduate to the inlet of the atmometer by
test specimens and the length comparator for measuring length
means of clear plastic tubing.
change shall conform to the requirements of Practice C490.
5.5.2 Operation—Use clear plastic tubing to connect a
5.2 Tamper—The tamper shall be made of a nonabsorptive,
squeeze bottle containing distilled or deionized water to one of
nonabrasive material such as medium-hard rubber or seasoned
the short glass tubes into the graduate. Force water into the
oak wood rendered nonabsorptive by immersion for 15 min in
graduate until it is about half full and then close the remaining
paraffin at approximately 392 °F [200 °C], and shall have a
glass tube into the graduate. Continue to force water through
cross section of ⁄2 by 1.0 in. [13 by 25 mm] and a convenient
the graduate into the atmometer until the filter paper is
length of about 6 in. [150 mm].The tamping face of the tamper
saturated and there are no air bubbles in the system. Open the
shall be flat and at right angles to the length of the tamper.
glasstubeintothegraduateandreleasepressureonthesqueeze
bottle gradually to avoid trapping air in the tube leading to the
5.3 Tamping Rod—The tamping rod shall be a straight steel
atmometer. Adjust the level of water in the graduate to
rod ⁄8 in. [10 mm] in diameter and not less than 10 in. [250
approximatelythe100-mLmark.Iftheatmometeristobeused
mm] in length, having at least the tamping end rounded to a
under variable temperature conditions, disconnect the squeeze
hemispherical tip of the same diameter.
bottle after filling the graduate to avoid the possibility of
5.4 Drying Room and Controls—A drying room with suit-
additional water being forced into the graduate. Permit evapo-
able racks shall be provided when storing specimens in air.The
rationofwaterfromthefilterpaperfor1hbeforerecordingthe
racks shall be designed for free circulation of air around
time and initial reading of the graduate. It is not permitted to
specimens, except for necessary supports, and shall be so
omit the waiting period during subsequent use of the atmom-
situated with respect to the nearest wall or other obstruction
eter provided the filter paper does not become dry. Change the
that air circulation is not restricted in the intervening space.
filter paper whenever it shows signs of contamination but not
The supports shall be horizontal and shall consist of two
less frequently than once every two weeks.
nonabsorptive members not deeper than 1 in. [25 mm] and
5.6 Filter Paper—The filter paper to be used with the
having a bearing area of not more than ⁄4 in. [6 mm] in width.
atmometershallbewhitewithasmoothsurfacetexture.Itshall
Conditioned air shall be circulated into and out of the room in
be 6 in. [152 mm] in diameter and 0.050 6 0.003 in. [1.27 6
a uniform manner so that the specified rate of evaporation is
0.08 mm] thick and shall have a cotton fiber content of not less
attained adjacent to all specimens.
than 75 weight %. The density shall be between 0.400 and
5.4.1 The air in the room shall be maintained at a tempera-
0.425 g/cm . The Mullen bursting strength shall not be less
ture of 73 63°F[23 6 2 °C] and a relative humidity of 50 6
than 50 psi [345 kPa].
4 %. The air movement past all specimens shall be such that
the rate of evaporation is 77 6 30-mL/24 h from an atmometer 3
NOTE 1—E and D filter paper No. 625 has been found suitable.
or 13 6 5-mL/24 h from a 400-mL Griffin low-form beaker
filled to ⁄4 in. [20 mm] from the top. The temperature and
relative humidity of the air in the room shall be measured with
either a sling or Assmann psychrometer at least twice each
The sole source of supply of the apparatus known to the committee at this time
workingday.ThepsychrometershallcomplywithTestMethod
is Ahlstrom Filtration Co., Mt. Holly Springs, PA 17065. If you are aware of
E337, except that thermometers having an overall length of 10
alternative suppliers, please provide this information to ASTM International
in. [250 mm] and marked in subdivisions of 0.5 °F [0.25 °C] Headquarters.Your comments will receive careful consideration at a meeting of the
responsible technical committee, which you may attend.
are permitted. The room shall be equipped with a means of
measuring and recording wet- and dry-bulb temperatures
continuously. Correction factors as indicated by the sling or
Assmann psychrometer shall be applied to the recorded data.
The rate of evaporation within the room shall be determined
daily by the use of the atmometer or by the loss of mass of
water from a 400-mLGriffin low-form beaker filled initially to
⁄4 in. [20 mm] from the top.
5.5 Atmometer—The atmometer shall be constructed as
shown in Fig. 1. FIG. 2 Atmometer Assembly
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C157/C157M − 08 (2014)
ASTM C157 FIGURES
Figure Di- SI Units Inch-Pound Units
mensions
A Adjustable torque handle Adjustable torque handle
1.4–1.7 Nm 12–15 in.lb
B Jam nut Jam nut
10–15 IMC ⁄8-in.–16 NC
C 10-mm diameter 1.5 IMC Thd. ⁄8-in. dia–16 NC Thd.
D 12-mm diameter 1.5 IMC Thd. ⁄2-in. dia–20 NC Thd.
E 64-mm diameter 2.50-in. diameter
F 64-mm diameter 2.50-in. diameter
G 57-mm diameter 2.25-in. diameter
H 52-mm diameter 2.06-in. diameter
I 51-mm diameter 2.00-in. diameter
J 14mm 0.56in.
K 8 mm 0.31 in.
L 13mm 0.50in.
M 3 mm 0.125 in.
N 8 mm 0.31 in.
O 19mm 0.75in.
P 32mm 1.25in.
Q 53mm 2.06in.
1 29
R 1.5-mm drill through 11.5-mm C’ ⁄16-in. drill through ⁄64-in. C’ drill
drill
1 1
32-mm deep tap 12-mm 1.5-mm 1 ⁄4-in. deep tap ⁄2-in.–20 Thd
IMF Thd
3 5 1
S 19 mm deep 16 mm C’ bore 6 ⁄4-in. deep ⁄8-in. C’ bore ⁄4 in.
mm deep deep
3 1
T 5-mm drill 3-mm deep C’ drill ⁄16-in. drill ⁄8-in. deep C’ drill
at 60° as shown at 60° as shown
through to center tapped hole through to center tapped hole
Instructions for Use—Remove the end and the outer side plates leaving the
U 3 mm 0.12 in. diameter
base, center side plate, and gage stud holders in place. Engage the machine
V 2 mm 0.09 in.
screw in the drilled and tapped end of the center side plate. Turn the thumbscrew
W 10mm 0.40in.
to loosen the bars.
X 60mm 2.36in.
FIG. 3 Device for Detaching 1-in. [25-mm] Square by 11 ⁄4-in.
Y 35mm 1.37in.
[285-mm] Bars from Center Side Plate of Double Molds
Z 6 mm 0.25 in.
AA 6mm 0.25in.
BB 4mm 0.15in.
CC 6mm 0.25in.
DD 23 mm 0.87 in.
EE 38 mm 1.50 in.
FF 25 to 75 mm 1 to 3 in.
GG 35 mm high 1.37 in. high
HH 100 mm 4 in.
II 130 mm 5 in.
JJ 8 cm–6.1 kg/m channel 3 in.–4.1 lb/ft channel
KK 20 mm ⁄4 in.
LL 330 mm 13 in.
MM 14–2.0 IMC Thd. ⁄2 in.–12 Thd.
NN 20 mm ⁄4 in.
OO 50 mm 2 in.
PP 20 mm ⁄4 in.
QQ 60 mm ⁄4 in.
RR 10 mm ⁄8 in.
SS Drill Cl. hole for Drill Cl. hole for
4.5–0.75 IMC machine screw 8–32 in. machine screw
TT 13 mm ⁄2 in.
NOTE 1—Dimensions shown are appropriate for one design of mold for
UU 25 mm 1 in.
3-in. [75-mm] square specimens. Change dimensions as required for other 3
VV 30 mm 1- ⁄16 in.
molds. 3
WW 60 mm 2- ⁄8 in.
FIG. 4 Device for Demolding Specimens from Single Molds XX 12.5 mm ⁄2 in.
YY 6-mm diameter steel rod ⁄4-in. diameter steel rod
ZZ 4.5–0.75 IMC × 16-mm machine 8–32 × ⁄8-in. machine screw
screw
5.7 Apparatus for Demolding Specimens—It is useful to
construct an apparatus for demolding specimens molded in
6. Sampling
double molds as detailed in Fig. 3 or to a different design that
6.1 Take samples according to the applicable provisions of
serves the same purpose. When this device is to be used, the
Practice C192/C192M from batches of hydraulic-cement mor-
center side plate of the double mold must be appropriately
tar or concrete made in the laboratory (Note 2).
drilled and tapped to receive the 8-32 by ⁄8 in. [4.5-0.74 IMC
by 16 mm] machine screw of the demolding thumbscrew. Fig.
NOTE 2—When collecting samples in nonstandard conditions, such as
4 shows the details of a suitable apparatus for demolding
field concrete, it is suggested that Practice C172 be followed. Field cast
specimens molded in single molds. specimens can show up to twice as much drying shrinkage as laboratory
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C157/C157M − 08 (2014)
cast specimens from the same materials and proportions.
a homogeneous specimen is obtained. After the top layer has
been compacted, strike off the mortar flush with the top of the
7. Test Specimens
mold, and smooth the surface with a few strokes of a trowel.
7.1 Mortar—The test specimen for mortar shall be a prism Immediately after completion of molding, loosen the device by
of 1-in. [25-mm] square cross-section and approximately 11 ⁄4 holding the gage studs in position at each end of the mold in
in. [285 mm] in length. Three specimens shall be prepared for order to prevent any restraint of the gage studs during initial
each test condition. shrinkage of the specimen.
7.2 Concrete—The test specimen for concrete, in which all
9.2 Concrete Specimens—Place the concrete in the mold in
of the aggregate passes a 2-in. [50-mm] sieve,
...
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.
´1 ´1
Designation: C157/C157M − 08 C157/C157M − 08 (Reapproved 2014)
Standard Test Method for
Length Change of Hardened Hydraulic-Cement Mortar and
Concrete
This standard is issued under the fixed designation C157/C157M; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
ε NOTE—Editorial corrections were made to Section 2 in Junein November 2014.
1. Scope*
1.1 This test method covers the determination of the length changes that are produced by causes other than externally applied
forces and temperature changes in hardened hydraulic-cement mortar and concrete specimens made in the laboratory and exposed
to controlled conditions of temperature and moisture.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. An exception is with regard
to sieve sizes and nominal size of aggregate, in which the SI values are the standard as stated in Specification E11. Within the text,
the SI units are shown in brackets. 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.
1.3 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.
2. Referenced Documents
2.1 ASTM Standards:
C125 Terminology Relating to Concrete and Concrete Aggregates
C143/C143M Test Method for Slump of Hydraulic-Cement Concrete
C172 Practice for Sampling Freshly Mixed Concrete
C192/C192M Practice for Making and Curing Concrete Test Specimens in the Laboratory
C305 Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic Consistency
C490 Practice for Use of Apparatus for the Determination of Length Change of Hardened Cement Paste, Mortar, and Concrete
C511 Specification for Mixing Rooms, Moist Cabinets, Moist Rooms, and Water Storage Tanks Used in the Testing of Hydraulic
Cements and Concretes
C596 Test Method for Drying Shrinkage of Mortar Containing Hydraulic Cement
C1437 Test Method for Flow of Hydraulic Cement Mortar
E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves
E337 Test Method for Measuring Humidity with a Psychrometer (the Measurement of Wet- and Dry-Bulb Temperatures)
3. Terminology
3.1 Definitions—The terms used in this test method are defined in Terminology C125.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 length change, n—an increase or decrease in the length of a test specimen that has been caused to change by any factor
other than externally applied forces and temperature changes.
This test method is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.68 on
Volume Change.
Current edition approved Oct. 1, 2008Oct. 1, 2014. Published November 2008November 2014. Originally approved in 1940. Last previous edition approved in 20062008
ε1
as C157/C157M – 06.C157/C157M – 08 . DOI: 10.1520/C0157_C0157M-08E01.10.1520/C0157_C0157M-08R14E01.
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.
*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
´1
C157/C157M − 08 (2014)
4. Significance and Use
4.1 Measurement of length change permits assessment of the potential for volumetric expansion or contraction of mortar or
concrete due to various causes other than applied force or temperature change. This test method is particularly useful for
comparative evaluation of this potential in different hydraulic-cement mortar or concrete mixtures.
4.2 This test method provides useful information for experimental purposes or for products that require testing under
nonstandard mixing, placing, handling, or curing conditions, such as high product workability or different demolding times.
Standard conditions are described in 5.4.1.
4.3 If conditions for mixing, curing, sampling, and storage other than specified in this test method are required, they shall be
reported but are not to be considered as standard conditions of this test method. Nonstandard conditions and the reasons for
departure from standard conditions shall be reported clearly and prominently with comparator values.
5. Apparatus
5.1 Molds and Length Comparator—The molds for casting test specimens and the length comparator for measuring length
change shall conform to the requirements of Practice C490.
5.2 Tamper—The tamper shall be made of a nonabsorptive, nonabrasive material such as medium-hard rubber or seasoned oak
wood rendered nonabsorptive by immersion for 15 min in paraffin at approximately 392 °F [200 °C], and shall have a cross section
of ⁄2 by 1.0 in. [13 by 25 mm] and a convenient length of about 6 in. [150 mm]. The tamping face of the tamper shall be flat and
at right angles to the length of the tamper.
5.3 Tamping Rod—The tamping rod shall be a straight steel rod ⁄8 in. [10 mm] in diameter and not less than 10 in. [250 mm]
in length, having at least the tamping end rounded to a hemispherical tip of the same diameter.
5.4 Drying Room and Controls—A drying room with suitable racks shall be provided when storing specimens in air. The racks
shall be designed for free circulation of air around specimens, except for necessary supports, and shall be so situated with respect
to the nearest wall or other obstruction that air circulation is not restricted in the intervening space. The supports shall be horizontal
and shall consist of two nonabsorptive members not deeper than 1 in. [25 mm] and having a bearing area of not more than ⁄4 in.
[6 mm] in width. Conditioned air shall be circulated into and out of the room in a uniform manner so that the specified rate of
evaporation is attained adjacent to all specimens.
5.4.1 The air in the room shall be maintained at a temperature of 73 6 3 °F [23 6 2 °C] and a relative humidity of 50 6 4 %.
The air movement past all specimens shall be such that the rate of evaporation is 77 6 30-mL/24 h from an atmometer or 13 6
5-mL/24 h from a 400-mL Griffin low-form beaker filled to ⁄4 in. [20 mm] from the top. The temperature and relative humidity
of the air in the room shall be measured with either a sling or Assmann psychrometer at least twice each working day. The
psychrometer shall comply with Test Method E337, except that thermometers having an overall length of 10 in. [250 mm] and
marked in subdivisions of 0.5 °F [0.25 °C] are permitted. The room shall be equipped with a means of measuring and recording
wet- and dry-bulb temperatures continuously. Correction factors as indicated by the sling or Assmann psychrometer shall be
applied to the recorded data. The rate of evaporation within the room shall be determined daily by the use of the atmometer or
by the loss of mass of water from a 400-mL Griffin low-form beaker filled initially to ⁄4 in. [20 mm] from the top.
5.5 Atmometer—The atmometer shall be constructed as shown in Fig. 1.
5.5.1 Mounting—Fig. 2 shows a suggested arrangement for operating the atmometer. Punch a central hole ⁄2 in. [13 mm] in
diameter in a filter paper, place it on the atmometer, and secure it in place while dry, by turning the torque handle only, until it
just starts to slip. Mount the atmometer on a stand with the filter paper in a horizontal position. Mount a 100-mL glass graduate
so that the 100-mL mark is from 1 to 3 in. [25 to 75 mm] below the level of the filter paper. Stopper the graduate so that entrance
is provided for two short glass tubes not extending to the water level and one long tube extending to the bottom of the graduate.
Connect the glass tubing leading from the bottom of the graduate to the inlet of the atmometer by means of clear plastic tubing.
5.5.2 Operation—Use clear plastic tubing to connect a squeeze bottle containing distilled or deionized water to one of the short
glass tubes into the graduate. Force water into the graduate until it is about half full and then close the remaining glass tube into
the graduate. Continue to force water through the graduate into the atmometer until the filter paper is saturated and there are no
air bubbles in the system. Open the glass tube into the graduate and release pressure on the squeeze bottle gradually to avoid
trapping air in the tube leading to the atmometer. Adjust the level of water in the graduate to approximately the 100-mL mark. If
the atmometer is to be used under variable temperature conditions, disconnect the squeeze bottle after filling the graduate to avoid
the possibility of additional water being forced into the graduate. Permit evaporation of water from the filter paper for 1 h before
recording the time and initial reading of the graduate. It is not permitted to omit the waiting period during subsequent use of the
atmometer provided the filter paper does not become dry. Change the filter paper whenever it shows signs of contamination but
not less frequently than once every two weeks.
5.6 Filter Paper—The filter paper to be used with the atmometer shall be white with a smooth surface texture. It shall be 6 in.
[152 mm] in diameter and 0.050 6 0.003 in. [1.27 6 0.08 mm] thick and shall have a cotton fiber content of not less than 75
weight %. The density shall be between 0.400 and 0.425 g/cm . The Mullen bursting strength shall not be less than 50 psi [345
kPa].
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C157/C157M − 08 (2014)
FIG. 1 Atmometer
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C157/C157M − 08 (2014)
FIG. 2 Atmometer Assembly
Instructions for Use—Remove the end and the outer side plates leaving the base, center side plate, and gage stud holders in place. Engage the machine screw in the
drilled and tapped end of the center side plate. Turn the thumbscrew to loosen the bars.
FIG. 3 Device for Detaching 1-in. [25-mm] Square by 11 ⁄4-in. [285-mm] Bars from Center Side Plate of Double Molds
NOTE 1—Dimensions shown are appropriate for one design of mold for 3-in. [75-mm] square specimens. Change dimensions as required for other
molds.
FIG. 4 Device for Demolding Specimens from Single Molds
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C157/C157M − 08 (2014)
NOTE 1—E and D filter paper No. 625 has been found suitable.
5.7 Apparatus for Demolding Specimens—It is useful to construct an apparatus for demolding specimens molded in double
molds as detailed in Fig. 3 or to a different design that serves the same purpose. When this device is to be used, the center side
plate of the double mold must be appropriately drilled and tapped to receive the 8-32 by ⁄8 in. [4.5-0.74 IMC by 16 mm] machine
screw of the demolding thumbscrew. Fig. 4 shows the details of a suitable apparatus for demolding specimens molded in single
molds.
The sole source of supply of the apparatus known to the committee at this time is Ahlstrom Filtration Co., Mt. Holly Springs, PA 17065. If you are aware of alternative
suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical
committee, which you may attend.
´1
C157/C157M − 08 (2014)
ASTM C157 FIGURES
Figure Di- SI Units Inch-Pound Units
mensions
A Adjustable torque handle Adjustable torque handle
1.4–1.7 Nm 12–15 in.lb
B Jam nut Jam nut
10–15 IMC ⁄8-in.–16 NC
C 10-mm diameter 1.5 IMC Thd. ⁄8-in. dia–16 NC Thd.
D 12-mm diameter 1.5 IMC Thd. ⁄2-in. dia–20 NC Thd.
E 64-mm diameter 2.50-in. diameter
F 64-mm diameter 2.50-in. diameter
G 57-mm diameter 2.25-in. diameter
H 52-mm diameter 2.06-in. diameter
I 51-mm diameter 2.00-in. diameter
J 14 mm 0.56 in.
K 8 mm 0.31 in.
L 13 mm 0.50 in.
M 3 mm 0.125 in.
N 8 mm 0.31 in.
O 19 mm 0.75 in.
P 32 mm 1.25 in.
Q 53 mm 2.06 in.
1 29
R 1.5-mm drill through 11.5-mm C’ ⁄16-in. drill through ⁄64-in. C’ drill
drill
1 1
32-mm deep tap 12-mm 1.5-mm 1 ⁄4-in. deep tap ⁄2-in.–20 Thd
IMF Thd
3 5 1
S 19 mm deep 16 mm C’ bore 6 ⁄4-in. deep ⁄8-in. C’ bore ⁄4 in.
mm deep deep
3 1
T 5-mm drill 3-mm deep C’ drill ⁄16-in. drill ⁄8-in. deep C’ drill
at 60° as shown at 60° as shown
through to center tapped hole through to center tapped hole
U 3 mm 0.12 in. diameter
V 2 mm 0.09 in.
W 10 mm 0.40 in.
X 60 mm 2.36 in.
Y 35 mm 1.37 in.
Z 6 mm 0.25 in.
AA 6 mm 0.25 in.
BB 4 mm 0.15 in.
CC 6 mm 0.25 in.
DD 23 mm 0.87 in.
EE 38 mm 1.50 in.
FF 25 to 75 mm 1 to 3 in.
GG 35 mm high 1.37 in. high
HH 100 mm 4 in.
II 130 mm 5 in.
JJ 8 cm–6.1 kg/m channel 3 in.–4.1 lb/ft channel
KK 20 mm ⁄4 in.
LL 330 mm 13 in.
MM 14–2.0 IMC Thd. ⁄2 in.–12 Thd.
NN 20 mm ⁄4 in.
OO 50 mm 2 in.
PP 20 mm ⁄4 in.
QQ 60 mm ⁄4 in.
RR 10 mm ⁄8 in.
SS Drill Cl. hole for Drill Cl. hole for
4.5–0.75 IMC machine screw 8–32 in. machine screw
TT 13 mm ⁄2 in.
UU 25 mm 1 in.
VV 30 mm 1- ⁄16 in.
WW 60 mm 2- ⁄8 in.
XX 12.5 mm ⁄2 in.
YY 6-mm diameter steel rod ⁄4-in. diameter steel rod
ZZ 4.5–0.75 IMC × 16-mm machine 8–32 × ⁄8-in. machine screw
screw
6. Sampling
6.1 Take samples according to the applicable provisions of Practice C192/C192M from batches of hydraulic-cement mortar or
concrete made in the laboratory (Note 2).
NOTE 2—When collecting samples in nonstandard conditions, such as field concrete, it is suggested that Practice C172 be followed. Field cast
specimens can show up to twice as much drying shrinkage as laboratory cast specimens from the same materials and proportions.
7. Test Specimens
7.1 Mortar—The test specimen for mortar shall be a prism of 1-in. [25-mm] square cross-section and approximately 11 ⁄4 in.
[285 mm] in length. Three specimens shall be prepared for each test condition.
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