ASTM C1078-87(1992)e1

Test Methods for Determining the Cement Content of Freshly Mixed Concrete (Withdrawn 1998)

General Information

• Status: Withdrawn
• Withdrawal Date: 09-Aug-1998
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: C09 - Concrete and Concrete Aggregates
• Drafting Committee: C09.60 - Testing Fresh Concrete

Standards Content (Sample)

ASTM C1078xEl 87 - 0759530 0507599 442 -
AMERICAN SCClElY FCR TESTING AND MATERIALS
Designation: C 1078 - 87 (Reapproved 1992)”
1916 Race St Philadelphia, Pa 19103
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Nb
If not listed in the current combined index, will appear in the next edition.
Standard Test Methods for
Determining the Cement Content of Freshly Mixed
Concrete’
This standard is issued under the fixed designation C 1078; 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 (6) indicates an editorial change since the last revision or reapprowl.
“NOTE--Editorial corrections were made in March 1992.
1. Scope from the concrete (those particles passing the finest sieve) are
uniformly suspended. A constant-volume representative
1.1 These test methods cover two procedures for deter-
sample of the cement suspension is obtained and diluted
mining the cement content of a sample of freshly mixed
with a known volume of nitric acid and water. The diluted
concrete. These methods are applicable to all freshly mixed
sample is agitated, without heat, to dissolve some of the
portland-cement concrete batches for which calibration can
calcium compounds in the cement. The calcium-ion concen-
be obtained in advance, except those containing certain
tration of the resulting solution is determined by manual
aggregates or admixtures, that, when washed over a 150~pm
volumetric titration in Procedure A or instrumental
(No. 100) sieve, yield significant and varying amounts of
fluorometric determination in Procedure B and is correlated
calcium ions in solution under the conditions of the test. The
to the cement content of the specimen by a previously
choice of which procedure to use is at the discretion of the
developed calibration curve.
user. The environment in which these test methods are used
may have some bearing on the choice.
4. Significance and Use
1.2 The values stated in inch-pound units are to be
regarded as the standard except in regard to sieve sizes which 4.1 These test methods can be used to determine vari-
are in accordance with Specification E 11. ability of cement content in a batch of concrete and the
1.3 This standard does not purport to address all of the variability of cement content between batches of nominally
safety problems, if any, associated with its use. It is the identical concrete. If these test methods are used to indicate
concrete uniformity, correct and appropriate sampling pro-
responsibility of the user of this standard to establish appro-
cedures must be followed. Sampling procedures are refer-
priate safety and health practices and determine the applica-
enced in Section 6 of these test methods.
bility of regulatory limitations prior to use.
4.2 The water-cement ratio of a concrete sample can be
2. Referenced Documents
estimated when these test methods are used in conjunction
with Test Methods C 1079.
2.1 ASTM Standards:
4.3 These test methods are not applicable to concretes
C 94 Specification for Ready-Mixed Concrete2
containing certain aggregates, or admixtures, that when
C 127 Test Method for Specific Gravity and Absorption of
washed over a 150~pm (No. 100) sieve yield significant and
Coarse Aggregate*
varying amounts of calcium ions in solution under the
C 138 Test Method for Unit Weight, Yield, and Air
conditions of the test. The variation of calcium ions will be
Content (Gravimetric) of Concrete
apparent when performing the calibration procedure. This
C 172 Practice for Sampling Fresh Concrete2
variation will result in the inability to achieve less than a 5 %
C 670 Practice for Preparing Precision and Bias State-
variation in the calibration test results or a linear calibration
ments for Test Methods for Construction Materials2
curve (see 9.4 and 15.4).
C 1079 Test Methods for Determining Water Content of
Freshly Mixed Concrete2
5. Purity of Reagents
E 11 Specification for Wire-Cloth Sieves for Testing
5.1 Purity of Reagents-Reagent grade chemicals shall be
Purposes3
used in all tests. Unless otherwise indicated, it is intended
3. Summary of Test Methods
that all reagents shall conform to the specifications of the
Committee on Analytical Reagents of the American Chem-
3.1 A given mass of freshly mixed concrete is washed with
ical Society, where such specifications are available.4 Other
a given volume of water over a nest of sieves. The water is
grades may be used, provided it is first ascertained that the
agitated so that the cement and other fine particles washed
reagent is of sufficiently high purity to permit its use without
I These test methods are under the jurisdiction of ASTM Committee C-9 on
Concrete and Concrete Aggregates and are the direct responsibility of Subcom-
4 “Reagent Chemicals, American Chemical Society Specifications,” Am. Chem-
mittee CO9.03.03 on Methods of Testing Fresh Concrete. ical Sot., Washington, DC. For suggestions on the testing of reagents not listed by
Current edition approved May 29, 1987. Published July 1987. the American Chemical Society, see “Reagent Chemicals and Standards,” by
z Annual Book of ASTM Standards, Vol 04.02.
Joseph Rosin, D. Van Nostrand Co., Inc., New York, NY, and the “United States
3 Annual Book of ASTM Standards. Vols 04.02 and 14.02. Pharmacopeia.”
ASTM Cl,078*EL 87 W 0759510 0507600 T94 D
'fjb Cl078
propeller, and a recirculating pump and hose. The
recirculating hose shall be fitted with a T connector and 3 ft
(0.9 m) of G-in. (6.4 mm) inside diameter, latex tubing to be
connected to the linked pipet. The working or rated capacity
of the tub shall be 10 gal (37.9 L). The inside dimensions of
the washing machine tub shall be large enough to hold a 15
5/16 by 12 5/16-in. (389 by 313-mm) nest of sieves. The
washing machine, nest of sieves, and linked pipets are shown
in Fig. 2. The cement suspension tank described in 13.1.5
may be fitted with the T connector and substituted for this
washing machine.
7.1.6 Sieve Nest, having a rectangular steel frame, 15 ‘/l6
by 12 ‘/16 by 8 in. (389 X 3 13 x 203 mm) with a 300~urn
a. Balance i. Stirrer
(No. 50) sieve at the bottom and a 4.75-mm (No. 4) sieve at
b. Hand scoop j. &ret, 100 mL
c. Sample tub k. Pipet, 25 mL mid-height. The 4.75-mm sieve shall be removable. There
I. Conical Beakers of Erfenmeyar flasks
d. Specimen tub
shall be an additional separate sieve frame, 4 in. (102 mm)
e. Washing machine m. Fixad-volume dispenser
deep, nested below the 300~pm sieve, and having a 150~urn
f. Sieve nest n. Carboys
(No. 100) sieve at the bottom. The combination of sieves
g. Linked pipet. 100 and 125 mL o. Wash Bottle, 500 mL
p. Dropping bottle
h. Automatic pipat, 300 mL
used for calibration and cement-content testing must be the
same. The 150~urn sieve may be omitted for siliceous line
Equipment Required for Determining the Cement Content
FIG. 1
aggregates but shall be used when a calcareous line aggregate
of Freshly Mixed Concrete Using Procedure A
is encountered. (A line aggregate is regarded as “calcareous”
when the results of a chemical analysis show in excess 20 ‘%
lessening the accuracy of the determination. A comparison
CaO.) If the cement suspension tank described in 13.1.5 is
of results obtained using the proposed grades with results
used, the sieve nest described in 13.1.6 shall be used instead
obtained using reagent grade chemicals shall be made to
of the nest described in this section.
ensure that the proposed grades are sufficiently pure, unless
7.1.7 Linked Pipets, 125 + IO-mL glass pipet with an
previous records confirm they are satisfactory.
automatic leveling and overflow device fitted with a three-
5.2 Purity of Water-Unless otherwise indicated, all refer-
way tap. To it is attached a 100 f lo-mL automatic pipet
ences to water shall be understood to mean distilled water or
with a three-way tap capable of emptying the smaller pipet’s
water of equal purity. (The primary use of the distilled water
contents through the 125 f lo-mL pipet without draining
is for reagent preparation.)
the contents out of the overllow device. The reproducibility
of the automatic pipet must be kO.20 %. The linked pipet
6. Sampling
apparatus is shown in Fig. 2.
6.1 The sample of concrete from which the cement-
7.1.8 Automatic Pipet, 300 + 25-mL automatic glass pipet
content test specimen is taken shall be representative of the
fitted with a three-way tap. The reproducibility of the
entire batch and have a mass of not less than 20 kg. It shall
automatic pipet must be 0.2 %.
be obtained in accordance with Specification C 94 or Prac-
7.1.9 Magnetic Stirrer, variable-speed magnetic stirrer
tice C 172. Specification C 94 outlines procedures for sam-
with a TFE-fluorocarbon-coated magnetic stirring rod.
pling for uniformity of concrete produced in truck mixers.
7.1.10 Buret, lOO-mL acrylic body Class A or B with a
polytetralluoroethylene (PTFE) plug. A three-pronged utility
PROCEDURE A-MANUAL VOLUMETRlC TITRATION
clamp, a support base, and rod are required to hold the
7. Apparatus
buret.
7.1.11 Pipet, 25-mL volumetric glass, Class A or B pipet.
7.1 The following comprises a recommended minimum
selection of apparatus for use in conducting the analysis.
NOTE 1-A rubber suction bulb is recommended for use during
pipetting of the 25-mL sample containing cement.
Apparatus other than that described in 7.1.1 through 7.1.14
can be used provided they serve the same function.5 A
7.1.12 Conical Beakers or Erlenmeyer Flasks, narrow-
photograph of an acceptable selection of apparatus is shown
mouth, glass, conical beakers or Erlenmeyer flasks. One
in Fig. 1.
500-mL and one 800- or lOOO-mL capacity.
7.1.1 Balance, having a minimum capacity of 2600 g, and
7.1.13 Fixed Volume Dispenser, 5-mL fixed-volume dis-
a sensitivity of at least 0.1 g.
penser of polyethylene with a polypropylene measuring
7.1.2 Shovels, Hand Scoops, and Rubber Gloves as re-
chamber.
quired.
7.1.14 Reagent Dispensing Containers, a 500-mL polyeth-
7.1.3 Sample Tub, 5-qt (4.7-L) polyethylene tub,
ylene wash bottle, a 30-mL polyethylene dropping bottle,
7.1.4 Specimen Tub, 2-qt (1.9-L) polyethylene tub.
two rectangular aspirator carboys of either 2- or 5-gal(7.6- or
7.1.5 Washing Machine, Domestic portable washing ma-
18.9-L) capacity, and amber rubber tubing, l/2 in. (12.7 mm)
chine. It must have a smooth interior, a side-mounted
in inside diameter by 20 ft (6.1 m) long.
8. Reagents
s Howdyshell, P. A., “Revised Operations Guide for a Chemical Technique to
8.1 Ammonium Hydroxide-Ammonium Chloride Bufer
Determine Water and Cement Content of Fresh Concrete,” Technical Report
M-2 12, U.S. Army Construction Engineering Research Laboratory, April 1977. Solution (pH = IO)-Add 142 mL of ammonium hydroxide
ASTM CLO?‘B*EL 87 - 0759510 050’i’bOl~ 920 m
e# C 1078
Flask containing
dilution water
Flask containing 5% nitric acid
U-U
(F) Cement/fine sand
suspension flasks
(E) Take-off point for cement/fin
sand suspension
(D) Recirculation hose
(B) Washing-machine tub
(C) P;mp
fitted with impeller
FIG. 2 Equipment for Preparing and Sampling Cement/Fine Sand Suspension Using Procedure A
9. Calibration
(NH,OH) (assay as NH, w/w 28-30 %) to 17.5 g of
ammonium chloride (NH&l) and dilute to 250 mL with
9.1 Aggregate Blank-Prepare a representative 2-kg
water. The ammonium hydroxide in the buffer solution
sample of concrete using the materials and mix proportions
evaporates rapidly. The solution shall be kept under cover
of the concrete to be tested minus the cement. The sample
other than when dispensing reagents to minimize evapora-
mass should weigh 2 kg minus the mass of cement that
tion.
would be contained in a 2-kg sample of concrete. To
8.2 Eriochrome Black T Indicator Solution--Dissolve 0.5 determine the relative calcium ion content of these materials
g of Eriochrome Black T, Color Index No. 14645, in 25 mL follow 10.2 to 10.5. Record the volume of EDTA solution
of triethanolamine. The indicator solution has a storage life required for the aggregate blank. If 3-kg specimens are tested,
of about two months. the procedure shall be followed for 3 kg instead of 2 kg.
9.2 Cement-Using the materials and mix proportions of
8.3 Nitric Acid Solution (1 + 19)-Add one volume of
the concrete to be tested, hand mix a 2.0-kg sample of
concentrated nitric acid (HNO,. sp gr 1.42) to 19 volumes of
concrete. (Weigh cement and water for this mix to the
water.
nearest gram and weigh aggregates to the nearest 10 g. Make
8.4 Di-Sodium Ethylenediamine Tetraacetate (0.01 M)-
sure all cement from tools, mixing bowl, and the like, is
Dissolve 3.72 f 0.01 g of disodium ethylenediamine tetra-
washed into the washing machine.) Determine the relative
acetate (EDTA) in water and dilute to 1 L. Store EDTA
calcium ion content of this mix by following the procedure
solution in polyethylene bottles.
in 10.2 to 10.5. Record the volume of EDTA solution
ASTM Cl1078*EL 87 - 0759510 0507602 867 -
required for the cement calibration specimen. 125-mL linked pipet. Squeeze the large-bore recirculating
hose again to direct the cement suspension into the pipet.
9.3 Cement Content versus EDTA Calibration Curve-To
construct the linear calibration curve for cement content (g) When the pipet is filled to the overflow device, switch off the
lower pipet tap and release the large-bore recirculating hose.
versus the volume of EDTA required, plot zero cement and
the volume of EDTA required for the aggregate blank (9.1) 10.3 Drain the 125-mL aliquot of cement suspension into
as one point. Plot the mass of cement in the 2-kg concrete the 800-mL beaker. Wash out the 125-mL linked pipet using
calibration sample and the volume of EDTA required (9.2) 100 mL of HN03 solution from the automatic pipet posi-
tioned above the 125-mL pipet. Leave the tap on the lower
as the other point. Connect the two points with a straight line
125mL linked pipet open during this washing so that the
to complete the calibration curve for these sources and types
of cement and aggregate, All unknown cement contents are acid wash solution will flow into the SOO-mL beaker. Dilute
linearly proportional in terms of calcium ion content6 An the cement-HN03 solution in the beaker with 300 mL of tap
example of a calibration curve is in 11.1. water from the 300-mL automatic pipet. Place a TFE-
fluorocarbon-coated magnetic stirring rod in a beaker and
9.4 Calibration Requirements-Both the cement calibra-
stir contents on a magnetic stirr
...