ASTM C1749-12

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Designation: C1749 − 12
Standard Guide for
Measurement of the Rheological Properties of Hydraulic
Cementious Paste Using a Rotational Rheometer
This standard is issued under the fixed designation C1749; 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 Moist Rooms, and Water Storage Tanks Used in the
Testing of Hydraulic Cements and Concretes
1.1 This guide covers description of several methods to
C1005 Specification for Reference Masses and Devices for
measure the rheological properties of fresh hydraulic cement
Determining Mass and Volume for Use in the Physical
paste. All methods are designed to determine the yield stress
Testing of Hydraulic Cements
and plastic viscosity of the material using commercially
C1738 Practice for High-Shear Mixing of Hydraulic Cement
available instruments and the Bingham model. Knowledge of
Pastes
these properties gives useful information on performance of
cement pastes in concrete.
2.2 Other Standards:
API Recommended Practice 10B Testing Well Cements,
1.2 The values stated in SI units are to be regarded as
American Petroleum Institute, Washington, DC (1997)
standard. No other units of measurement are included in this
ISO10426-2(2003) PetroleumandNaturalGasIndustries—
standard.
Cements and Materials for Well Cementing—Part 2:
1.3 This guide offers an organized collection of information
Testing of Well Cements—Section 5.2
or a series of options and does not recommend a specific
course of action. This document cannot replace education or
3. Terminology
experience and should be used in conjunction with professional
judgment. Not all aspects of this guide may be applicable in all 3.1 Definitions—For definitions of terms used in this test
method, refer to Terminology C125 and C219.
circumstances. This ASTM standard is not intended to repre-
sent or replace the standard of care by which the adequacy of 3,4
3.2 Definitions of Terms Specific to This Standard:
a given professional service must be judged, nor should this
3.2.1 apparent viscosity, n—the shear stress divided by rate
document be applied without consideration of a project’s many
of shear, in units of Pa.s.
unique aspects. The word “Standard” in the title of this
3.2.2 plastic viscosity, n—in the plastic (Bingham) model,
document means only that the document has been approved
through the ASTM consensus process. the slope of the shear stress – shear rate curve, in units of Pa.s.
1.4 This standard does not purport to address all of the
3.2.3 thixotropy, n—a decrease of the apparent viscosity
safety concerns, if any, associated with its use. It is the
under constant shear stress or shear rate followed by a gradual
responsibility of the user of this standard to establish appro-
recovery when the stress or shear rate is removed.
priate safety and health practices and determine the applica-
3.2.4 yield stress, n—the stress corresponding to the transi-
bility of regulatory limitations prior to use.
tion from elastic to plastic deformation, in units of Pa; it is also
referred to as the stress needed to initiate flow. It would be
2. Referenced Documents
calculated using the Bingham model in this guide.
2.1 ASTM Standards:
3.2.5 Bingham model, n—a rheological model for materials
C305 Practice for Mechanical Mixing of Hydraulic Cement
Pastes and Mortars of Plastic Consistency with non-zero yield stress and a linear relationship between
shear rate and shear stress, following the equation: τ = τ +
C511 Specification for Mixing Rooms, Moist Cabinets,
B
γ˙η ; where τ Yield stress in Pa, γ˙ Shear rate in 1/s, τ Shear
pl B
stress in Pa, and η Plastic viscosity in Pa.s.
pl
This guide is under the jurisdiction of ASTM Committee C01 on Cement and
is the direct responsibility of Subcommittee C01.22 on Workability.
Current edition approved Feb. 1, 2012. Published March 2012.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or H.A. Barnes, J.F. Hutton and K.Walters,An Introduction to Rheology, Elsevier
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM (1989).
Standards volume information, refer to the standard’s Document Summary page on Hackley V.A., Ferraris C.F., “The Use of Nomenclature in Dispersion Science
the ASTM website. and Technology” NIST Recommended Practice Guide, SP 960-3, 2001.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1749 − 12
4. Significance and Use 7.1.2 The rheometer geometry shall provide a simple shear-
ing flow (laminar, without turbulence). Allowable geometries
4.1 Rheological properties determined using this guide in-
and their equations for computing stress and strain rate from
clude plastic viscosity and yield stress as defined by the
the measured values of rotational speed and torque are de-
Bingham model and apparent viscosity.
scribed in section 7.4.
4.2 Rheological properties provide information about the
7.2 The rotational rheometer shall be capable of measuring
workability of cement paste. As an example, the yield stress
-1 -1
shear stress at strain rates in the range from 0.1 s to 600 s .
and plastic viscosity indicate the behavior of a specific cement
The range of shear rates will be selected by the operator
paste composition.As another example, the apparent viscosity
depending on the geometry used. At least five measurements
indicates what energy is required to move the suspension at a
need to be recorded.
given strain rate. This test may be used to measure flowability
NOTE 1—Most experiments found in the literature do not use the full
of a cement paste or the influence of a specific material or
range of shear rates prescribed here. For example, most parallel plate
-1 -1
combination of materials on flowability.
measurements are done between 0.1 s to 50 s . The selection of the
shear rate range might take into account the exact geometry of the
4.3 Rheological properties may be sensitive to the proce-
rheometer.
dure being used. This guide describes procedures that are
7.3 Regularly check the calibration and zeroing of the
expected to provide reproducible results.
apparatus, as discussed in section 7.9.
5. Summary of Guide
7.4 Rheometer Geometry:
5.1 This guide provides procedures for the determination of
7.4.1 The rheometer geometries described in this section
rheological properties of fresh cement paste using a rotational
provide simple shearing flow, essential for reliable computa-
rheometer with geometries, such as parallel plate, narrow-gap
tion of stress and strain rates. The equation for computation of
and wide gap concentric cylinders.
stress and strain rates is given for each geometry.
NOTE 2—The following assumptions were made to develop the equa-
6. Interferences
tions that appear in this section: (1) the fluid is homogeneous, (2) slip at
6.1 Rheological properties may be sensitive to the
the wall is negligible, and (3) the flow regime is laminar.
procedure, so a comparison of properties obtained using
7.4.2 Selection of the geometry of the rheometer. Three
different procedures is not recommended, unless relative vis-
geometries are described here: narrow-gap concentric
cosity(ratiobetweentheplasticviscosityofamaterialsandthe
cylinders, wide-gap concentric cylinders, and parallel plates.
plastic viscosity of a reference material, both measured using
The selection of the geometry should be based on the type of
the same rheometer) is considered.
rotational rheometer available. One criterion to select between
6.2 Rheological properties may be sensitive to the shear
the narrow-gap and the wide-gap should be based on the
history of the sample, so comparison of properties using
maximum size of the particles in the cement tested.
different mixing procedures is not recommended.
7.4.2.1 Narrow-Gap Concentric Cylinder—With this type
of rheometer, the sample is confined between two concentric
6.3 Pastemixtures(waterandcementparticles)thatarevery
cylinders of radii R and R (R >R ), one of which, the rotor,
1 2 2 1
fluid may yield erroneous data using this procedure due to
is rotating at a constant rotational speed Ω and the other is
settling of particles. Such settling is especially likely in shear
stationary. The rotation of the rotor in the presence of the
thinning and thixotropic mixtures.
sample produces a torque that is measured at the wall of the
6.4 Larger cement particles or aggregations of cement
inner cylinder. The cylinder radii should be selected such that
particles may block flow in a narrow-gap rheometer and
the shear stress is uniform across the gap. This condition is
thereby increase the shear stress.The gap between the shearing
assumed to be satisfied if:
surfaces needs to be selected with consideration of the particle
R
size of the material to be tested. Depending on the gap size, it
.5 0.92 (1)
S D
R
may be necessary to remove larger particles by sieving or
otherwise prevent segregation.
where R is the radius of the inner rotating cylinder (m) and
R is the radius of the outer stationary cylinder (m).
6.5 Incorporation of air in the paste during mixing reduces
To prevent slip (development of a liquid layer at the wall of
viscosity and increases flow.
the rotating cylinder that produces an anomalously low stress),
6.6 The time of testing after initial contact of cement with
the surface of cylinders may be serrated or at least rendered
water influences the results.
rough by attaching a sand paper, sand blasting, or other
methods that roughen the surface such as serration.
7. Apparatus
The nominal shear rate and stress are calculated at the inner
7.1 General Description:
cylinder wall by the following expression:
7.1.1 The apparatus shall be a rotational rheometer in which
R 3Ω
the sample is confined between two surfaces (called the 2 1
˙γ 5 (2)
R 2 R
shearing surfaces), one of which is rotating at a constant 2 1
rotational speed, Ω and the other being stationary. The appa-
ratus shall measure both the rotational speed and the torque
DIN 53019-1:2008, Viscometry—Measurement of v
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