ASTM C115-96a

Standard Test Method for Fineness of Portland Cement by the Turbidimeter

SCOPE
1.1 This test method covers determination of the fineness of portland cement as represented by a calculated measure of specific surface, expressed as square centimetres of total surface area per gram, or square meters of total surface area per kilogram, of cement, using the Wagner turbidimeter.  
1.2 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.  
1.3 The values stated in SI units are to regarded as the standard. The inch-pound equivalents may be approximate.

General Information

• Status: Historical
• Publication Date: 31-Dec-1993
• ICS: 91.100.10 - Cement. Gypsum. Lime. Mortar
• Technical Committee: C01 - Cement
• Drafting Committee: C01.25 - Fineness

Relations

• Replaced By: ASTM C115-96a(2003) - Standard Test Method for Fineness of Portland Cement by the Turbidimeter
• Effective Date: 10-Jul-2003

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: C 115 – 96a
Standard Test Method for
Fineness of Portland Cement by the Turbidimeter
This standard is issued under the fixed designation C 115; 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.
1. Scope and adjusted so that approximately parallel rays of light pass
through a suspension of the cement to be tested and impinge
1.1 This test method covers determination of the fineness of
upon the sensitive plate of a photoelectric cell. The current
portland cement as represented by a calculated measure of
generated in the cell is measured by means of a microammeter
specific surface, expressed as square centimetres of total
and the indicated reading is a measure of the turbidity of the
surface area per gram, or square metres of total surface area per
suspension. General considerations indicate that turbidity is in
kilogram, of cement, using the Wagner turbidimeter.
turn a measure of the surface area of the suspended sample of
1.2 This standard does not purport to address all of the
cement. The apparatus shall consist specifically of the parts
safety concerns, if any, associated with its use. It is the
described in 4.2-4.7 and shall be constructed in accordance
responsibility of the user of this standard to establish appro-
with the detailed design and dimensional requirements shown
priate safety and health practices and determine the applica-
in Fig. 1 and Table 1, except that the case may be either of
bility of regulatory limitations prior to use.
wood or of metal.
1.3 The values stated in SI units are to regarded as the
4.2 Turbidimeter, mounted in a suitable wood or metal case
standard. The inch-pound equivalents may be approximate.
including the following features:
2. Referenced Documents
4.2.1 Source of Light—The source of light (Fig. 1) shall
consist of a concentrated-filament electric lamp of between 3
2.1 ASTM Standards:
and 6 cd operated by a source of constant emf. The lamp shall
C 114 Test Methods for Chemical Analysis of Hydraulic
be mounted rigidly in the socket. A clean, bright parabolic
Cement
metallic reflector shall be rigidly mounted behind the lamp,
C 430 Test Method for Fineness of Hydraulic Cement by
focused so that approximately parallel rays of light will pass
the 45-μm (No. 325) Sieve
through the sedimentation tank and impinge upon the photo-
C 670 Practice for Preparing Precision and Bias Statements
electric cell. The light intensity shall be regulated by two
for Test Methods for Construction Materials
rheostats of approximately 6 and 30 V, respectively, and they
3. Significance and Use
shall possess such characteristics that uniform changes in light
intensity may be obtained over the full range of resistance. The
3.1 The purpose of this test method is to determine whether
rheostats shall be mounted in parallel with each other and in
or not the hydraulic cement under test meets the Wagner
series with the lamp.
turbidimetric fineness requirements of the applicable hydraulic
4.2.2 Heat-Absorbing Device—The light shall pass through
cement specification for which the test is being made. Fineness
a suitable heat absorbing device before entering the sedimen-
of the cement component is only one of the many character-
tation tank in order that radiant heat from the beam shall be
istics that influence the strength capabilities of concrete.
absorbed, the device being either (1) a water cell or (2)a
4. Apparatus
special heat-absorbing glass filter. The water cell shall be made
from 76-mm (3-in.) outside diameter seamless brass tubing,
4.1 Nature of Apparatus—The Wagner turbidimeter consists
3-mm ( ⁄8-in.) thick wall, 102-mm (4 in.) in length with glass
essentially of a source of light maintained at constant intensity
windows sealed in the ends. The cell shall contain a hole for
filling with distilled water. The hole shall be sealed with a
This test method is under the jurisdiction of ASTM Committee C-1 on Cement
metal plug. The cell, when mounted on the movable shelf, may
and is the direct responsibility of Subcommittee C01.25 on Fineness.
Current edition approved Dec. 10, 1996. Published February 1997. Originally
have the plug in either the top or bottom position. The
published as C 115 – 34 T. Last previous edition C 115 – 96.
heat-absorbing device shall be so arranged that essentially all
This turbidimeter was developed by L. A. Wagner, Research Associate of the
rays of light entering the sedimentation tank shall first pass
Cement Reference Laboratory, National Institute of Standards and Technology,
through the heat-absorbing device.
Washington, DC. A description of the apparatus and the original mathematical
derivations of formulas used are given in the paper: Wagner, L. A., “A Rapid Method
4.2.3 Retarding Filter—A light-retarding glass or other
for the Determination of the Specific Surface of Portland Cement,” Proceedings,
device shall be provided that will reduce the intensity of light
ASTM, ASTEA, Vol 33, Part II, 1933, p. 553.
from that corresponding to 100 μA to a reading of 20 to 30 μA.
Annual Book of ASTM Standards, Vol 04.01.
Annual Book of ASTM Standards, Vol 04.02. The light intensity shall be uniformly retarded over the entire
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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C115
hood shall be on a straight line which is parallel to the shelf.
The sedimentation tank shall be mounted on a base which is
independent of the rest of the apparatus so that the tank shall be
free from vibration caused by moving the shelf. Care shall be
taken that the shelf shall be level at all points of elevation and
that the tank shall be normal to the shelf. The distance between
the tank and the edges of the opening in the shelf shall vary not
more than ⁄64 in. (0.4 mm) between the “30–50” and “0”
Microammeter Internal Resistance 5 90 V
positions. The level of the light beam with reference to the
Shunt Equivalent Resistance:
470 3 100
surface of the suspension shall be indicated by a pointer which
470 V in parallel with 100V5 5 82 V
470 1 100
Meter & Shunt Equivalent + Resistance: will travel along a scale mounted on the cabinet. The zero of
90 3 82
the scale shall indicate that position at which the center lines of
90 V in parallel with 82V5 5 43 V
90 1 82
Series Resistance 5 90−43 5 47 V the slots for the light beam are at the same elevation as the
FIG. 1 Illustrated Example of D’Arsonval Meter Circuit for I
r surface of the liquid in the tank when filled to the 335-mL
Determination
level. The lines on the scale to be marked 7.5, 10, 15, 20, 25,
and 30–50, shall be located at distances from the zero mark
area of that portion of the cell which is exposed to light during equal to suspension depth values, h, in Table 2. The scale, when
a test. The retarding filter shall be mounted in a carrier on the compared with a standard scale accurate to within 0.1 mm at all
shield and shall be capable of being swung out of the light path points, shall not show a deviation at any point greater than 0.25
mm and shall indicate the positions at which the pointer should
by means of a handle.
4.2.4 Sedimentation Tank—The sedimentation tank shall be be located when turbidity readings for these values of h are
3 1
taken. The interior of the turbidimeter cabinet and the exterior
either (1) constructed of 5 to 6-mm ( ⁄16 to ⁄4-in.) plate glass or
borosilicate glass cemented or sealed together to form a surfaces of the shelf, the parabolic reflector, the heat absorbing
device, the shield, and the photoelectric cell hood shall be
rectangular tank, or (2) a molded glass tank having walls
approximately 5-mm ( ⁄16 in.) thick with plane surfaces. The painted with a dull flat black paint.
inside dimensions of the rectangular tank shall be 51 mm by 38
NOTE 1—The requirement of the 0 to 50 markings on the scale shall
mm (2 by 1 ⁄2 in.) by 203 mm (8 in.) in height. The permissible
apply only to new Wagner Turbidimeters and not to equipment in use
variation on the inside dimensions of the tank shall be 62.5
which meets the other requirements of this method.
mm (0.1 in.) in length and 60.76 mm (0.03 in.) in width. The
4.3 Microammeters:
51-mm faces of the tank shall be equidistant within 0.25 mm
4.3.1 D’Arsonval-Type Microammeters shall have a range
(0.1 in.) at all points. A mark shall be placed on the side of the
from 0 to 50 μA and shall be readable to 0.1 μA. New
tank to indicate a volumetric content of 335 mL, which is the
microammeters shall be accurate to 60.5 % of full scale value
level to which the tank will be filled in a test. A tank filled to
at any part of the scale value at any part of the scale at 77°F
the mark with clear kerosine and placed in the turbidimeter
(25°C). For microammeters, in use, the accuracy shall be the
light beam shall yield uniform microammeter readings, within
same as for new instruments except that the accuracy at 40 and
60.1 μA, for the entire usable portion of the tank.
50 μA shall be 61 % of full scale. The internal resistance of the
4.2.5 Photoelectric Cell—The means of measuring the light
microammeter shall be between 50 and 150V . The microam-
intensity shall be a sensitive photoelectric cell connected
meter shall not be mounted upon a working surface containing
directly to a microammeter. A hood with a horizontal slot 13
or consisting of iron or steel, or near other magnetic influence.
1 3
mm ( ⁄2 in.) in height by 35 mm (1 ⁄8 in.) in width shall be
4.3.2 Digital Microammeter:
mounted over the photoelectric cell. The front of the hood shall
be 256 1mm(1 6 ⁄16 in.) in front of the face of the cell. The NOTE 2—A meter with a range of 199.9 μA is satisfactory for use and
enables the operator to read the theoretical I directly without supplemen-
face of the photocell shall be parallel to the tank faces within 0
tary devices. The high internal resistance of the digital microammeter does
0.5 mm (0.02 in.).
not affect the linearity of readings at the light intensity levels encountered
4.2.6 Shield—A metallic shield having a slot 16 mm ( ⁄8 in.)
in a Wagner turbidimetric determination of fineness.
in height by 38 mm (1 ⁄2 in.) in width, as indicated in Fig. 1,
4.4 Source of Current—A 6-V automobile starting and
shall be placed between the heat absorbing device and the
lighting storage battery or a source of constant emf shall be
sedimentation tank.
used for supplying current to the lamp.
4.2.7 Elevating Device—The source of the light, the heat-
4.5 Sieve—The sieve shall conform to the requirements of
absorbing device, the photoelectric cell, the retarding filter, and
Test Method C 430.
the shield shall be mounted on a movable shelf which may be
4.6 Stirring Apparatus—The stirring apparatus shall consist
raised or lowered by two connected lead screws, and which
of either (1) a cylindrical brush, 19 mm ( ⁄4 in.) in diameter and
may be readily and accurately adjusted so that the turbidity of
about 45 mm (1 ⁄4 in.) in length, with an end approximately
the suspension may be determined at any desired depth. The
fitting the contour of the bottom of a 22-mm ( ⁄8-in.) diameter
center of the light source, the heat absorbing device, the
test tube, or (2) any other stirring device that will be equally
photocell, the center of the slots of the metal shield, and the
efficient in dispersion as measured by specific surface deter-
minations on a standard sample. The stirring apparatus shall
Weston Photronic type, Model 594YY is acceptable. rotate at a speed of approximately 3500 r/min.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
C115
FIG. 2 Dimensional Details of Turbidimeter Fineness Test Apparatus (see Table 1)
TABLE 1 Turbidimeter Apparatus Dimensions (see Fig. 1)
Letter mm in. Letter mm in.
A 445 17 ⁄2 T51 2
1 7
B 438 17 ⁄4 U 22.2 ⁄8
C 381 15 V 34.9 1 ⁄8
1 1
D 105 4 ⁄8 W13 ⁄2
1 1
E 3.0 ⁄8 X38 1 ⁄2
1 5
F 28.6 1 ⁄8 Y 15.9 ⁄8
3 1
G 85.7 3 ⁄8 Z38 6 0.76 1 ⁄2 6 0.03
H 33.3 1 ⁄16 AA 51 6 2.5 2 6 0.10
I 102 4 AB 267 10 ⁄2
A
9 5
J 39.7 1 ⁄16 AC . ⁄8
A
K 55.6 2 ⁄16 AD . 11
9 9
L 65.1 2 ⁄16 AE 39.7 1 ⁄16
1 3
M 28.6 1 ⁄8 AF 55.6 2 ⁄16
1 5
N 3.0 ⁄8 AG 66.7 2 ⁄8
O 51 2 AH 203 8
P 51 2 AI 23.6 0.93
A A
1 1
Q 3.0 ⁄8 AJ 1.38 3 ⁄2
A A
R 61.1 2 ⁄32 AK cm in.
S 69.8 2 ⁄4
A
These are pure numbers such as parts of a thread designation and numbers of links per unit; consequently, they do not correspond with the column titles.
4.7 Timing Buret—The time of settling for the different- to the limiting dimensions given in Table 3. The graduation
sized particles shall be obtained by use of a buret from which lines on the buret shall be complete circles. A filter made of No.
kerosine is allowed to flow. The buret shall consist of a glass 325 (45-μm) wire cloth shall be used with the timing buret and
tube having a capillary tube fused into the lower end. The a cover shall be placed over the top of the buret when it is not
upper end of the large tube shall be flared to serve as a funnel in use.
for introducing kerosine into the tube. The buret shall conform 4.8 Weights and Weighing Devices, shall conform to the
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
C115
TABLE 2 Values of h, d, and h/d to be Used in Calibration of the
r 5 density of kerosine, Mg/m at the temperature of
Turbidimeter Apparatus
calibration,
Particle Depthof h/d
h 5 depth of suspension to level of light, cm, and
Diameter, d,μm Suspension, h,cm
d 5 diameter of particle, μm.
50 15 0.00600
Values of h/d re given in Table 2.
45 15 0.00741
40 15 0.00938
7.1.1.2 Fill the buret with kerosine at the calibrating tem-
35 15 0.01224
perature, start a timing clock at the instant the kerosine in the
30 15 0.01667
buret drains past the zero line, and mark on the buret the levels
25 13.1 0.0210
20 10 0.0250
reached by the draining kerosine for each of the time intervals,
15 6.6 0.0293
t, calculated as described above. At these marks, etch perma-
10 3.3 0.0330
nent lines and numbers on the buret indicating the correspond-
7.5 2.1 0.0373
ing diameters (Note 5). The construction and the graduation of
the bu
...