Comparison of concrete rheometers:

International tests at MB

(Cleveland OH, USA)

 in May, 2003

Editors:

 Chiara F. Ferraris, Lynn E. Brower

Authors (alphabetical order):

Denis Beaupré, Frédéric Chapdelaine,

Peter Domone, Eric Koehler, Lin Shen, Mohammed Sonebi,

Leslie Struble, David Tepke, Olafur Wallevik,

Jon E. Wallevik

NISTIR 7154
NISTIR 7154

Comparison of concrete rheometers:

International tests at MB

(Cleveland OH, USA)

 in May, 2003

Editors:

Chiara F. Ferraris, National Institute of Standards and Technology (USA)

Lynn E. Brower, Master Builders Technologies (USA)

Authors (in alphabetical order):

Denis Beaupré, Laval Univ., (Canada)

Frédéric Chapdelaine, Laval Univ (Canada)

Peter Domone, University College London (UK)

Eric Koehler, University of Texas, Austin (USA)

Lin Shen, Univ. of Illinois at Urbana-Champaign (USA)

Mohammed Sonebi, Advanced Concrete and Masonry Centre (UK)

Leslie Struble, Univ. of Illinois at Urbana-Champaign (USA)

David Tepke, Pennsylvania State Univ. (USA)

Olafur Wallevik, The Icelandic Building Research Institute, (Iceland)

Jon E. Wallevik, Norwegian Univ. of Science and Technology, (Norway)

September 2004

U.S. DEPARTMENT OF COMMERCE

Donald L. Evans, Secretary

TECHNOLOGY ADMINISTRATION

Philip J. Bond, Under Secretary of Commerce and Technology

NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY

Arden L. Bement, Jr., Director
Disclaimer

Commercial equipment, instruments, and materials mentioned in this

paper are identified to foster understanding. Such identification does not

imply recommendation or endorsement by the National Institute of

Standards and Technology (NIST), nor does it imply that the materials or

equipment identified are necessarily the best available for the purpose.

During the trial in Cleveland (OH, USA), on May 2003, to ensure

proper use, a person designated by the designer or the designer himself

operated the instruments and described their operation in this report. After

each test all data were immediately collected in electronic form on specially

labeled diskettes/CD-ROMs, for later analysis.

The role of NIST was to coordinate and foster the rheometer study.

Dr. Chiara Ferraris is the chair of ACI 236A, “Workability of Fresh

Concrete”, and in this role she organized the tests and edited the report. She

is not one of the authors, but only an editor. Lynn Brower, co-editor, is the

secretary of ACI 236A.

The opinions expressed in this report are not endorsed by NIST

and they reflect only the opinion of the authors.
Preparation of the report

Editors

Chiara F. Ferraris, National Institute of Standards and Technology, Gaithersburg

(USA)

Lynn Brower, Master Builders, Cleveland OH (USA)

Authors (alphabetical order)

Denis Beaupré, Laval Univ., Quebec (Canada)

Frédéric Chapdelaine, Laval Univ., Quebec (Canada)

Peter Domone, University College London (UK)

Eric Koehler, University of Texas, Austin (USA)

Lin Shen, Univ. of Illinois at Urbana-Champaign (USA)

Mohammed Sonebi, Advanced Concrete and Masonry Centre, Paisley (UK)

Leslie Struble, Univ. of Illinois at Urbana-Champaign (USA)

David Tepke, Pennsylvania State Univ. (USA)

Jon E. Wallevik, Norwegian Univ. of Science and Technology, Trondheim (Norway)

Olafur Wallevik, The Icelandic Building Research Institute, Reykjavik (Iceland)

Contact

Chiara F. Ferraris

NIST

100 Bureau drive, MS 8621, Gaithersburg MD 20899 (USA)

Phone: +301-975 6711 Fax: +301-990 6891

E-mail: clarissa@nist.gov

 Participants in the tests at MB in Cleveland (OH), USA

1st row (left to right): Jinhua Jin, Jon Wallevik, Joe Daczko, Chiara Ferraris, Kevin M.

Murnin, Lynn Brower, Frédéric Chapdelaine, Celik Ozyildirin

2nd Row (left to right): Mohammed Sonebi, Gary Crawford, Leif Wathne, Mark

Piechuta, George Lianopoulos, Tyler Agner, Eric Koehler, Mark Kurtz, Denis Beaupre,

David Tepke, Olafur Wallevik

Affiliations of participants (in alphabetical order): (

*

 not present)

Advanced Concrete and Masonry Centre, Paisley (UK): Mohammed Sonebi

FHWA (USA): Gary Crawford, Leif Wathne

The Icelandic Building Research Institute, Reykjavik (Iceland): Olafur Wallevik

Laval Univ., Quebec (Canada): Denis Beaupré, Frédéric Chapdelaine

Master Builders, Cleveland OH (USA): Tyler Agner, Lynn Brower, Joseph Daczko,

Eric Kinzle, Mark Kurtz, George Lianopoulos, Mark Piechuta

National Institute of Standards and Technology, Gaithersburg (USA): Chiara F.

Ferraris, Nicos Martys

Norwegian Univ. of Science and Technology, Trondheim (Norway): Jon E. Wallevik

Pennsylvania State Univ. (USA): David Tepke

University College London (UK): Peter Domone*, Jinhua Jin

Univ. of Illinois at Urbana-Champaign (USA): Lin Shen*

, Leslie Struble*

University of Texas, Austin (USA): Eric Koehler, Kainan Bodenlos

Virginia Transportation Research Council (USA): Celik Ozyildirin

W.R. Grace & Co. (USA): Kevin M. Murnin

Foreword

The American Concrete Institute (ACI) sub-committee 236A, “Workability of

Fresh Concrete,” upon its creation in fall 1999, immediately faced the task of determining

appropriate methods to measure concrete workability. Using a material science-based

approach, workability should be defined using rheological methods. The instrument most

used for determining rheological parameters is a rheometer. There are several concrete

rheometers used around the world that have significant design differences, but no

standard method with which to compare their results. ACI 236A members determined

that, as no reference material was available, one method to compare the rheometers

would be to test them under the same conditions using the same concrete mixtures. A

tentative analysis comparing two rheometers was performed [1, 2] but did not involve

most of the available rheometer designs. A first set of round-robin testing was organized

in 2000, allowing the direct comparison of five types of rheometers [3]. This first

comparison test was sponsored by the Concrete Research Council (CRC) of ACI and by

industry. It was held at the Laboratoire Central des Ponts et Chaussées (LCPC) facility in

Nantes, France, on October 23-27, 2000. The rheometers selected included commercially

available concrete rheometers (four), and one coaxial concrete rheometer developed for

research.

After the test and subsequent report it was apparent that some issues were still

unresolved; therefore ACI 236A committee requested an extension grant from CRC and

more industrial support to conduct a second set of round-robin testing. The second test

was performed on May 19-23, 2003, in the laboratory of Masters Builders, a Degussa

Construction Chemical company, in Cleveland OH, (USA).

The authors of this report are principal investigators who participated in this

second test and contributed to the report. This report describes the tests performed and

the results obtained. Following the same procedure as in the first comparison test, this

report was not published as an ACI document and therefore was not submitted to the

Technical Activities Committee (TAC) for approval. There are two reasons that this is

not an ACI document: 1) ACI documents are guidelines and practice recommendations,

not research reports; 2) all ACI reports are consensus documents balloted and approved

by the members of a committee, while this report only reflects the views and opinions of

the authors. All members of ACI 236A were invited to review the document prior to

publication (as shown in the acknowledgements). It was also discussed during the regular

meetings of ACI 236A during Fall 2003 and Spring 2004.
Acknowledgements

This project was not possible without the financial support of the ACI Concrete Research

Council. Its support offset the cost of the transportation of the rheometers from Canada

and UK to the test site at Master Builders (MB), a Degussa Construction Chemicals

Company, in Cleveland, Ohio (USA). We are thankful for the hospitality and the

professionalism of the staff of MB, who welcomed the international team for the

weeklong tests. We would like to acknowledge the participation of MB staff, in

particular: Tyler Agner, Lynn Brower, Joseph Daczko, Eric Kinzle, Mark Kurtz, George

Lianopoulos, and Mark Piechuta. They organized the tests, prepared and tested all of the

concrete used for this project, and conducted all of the concrete quality control

measurements.

We would also like to thank all the participants and their organizations for their

involvement in the planning and execution of this comparison. Their names are listed in

the participants list placed before the foreword. Also, MB should be thanked for

providing their expertise to administer the funds provided by CRC.

The authors would also like to thank all the reviewers for their efforts in reading this

rather large report (in alphabetical order): Phil Banfill (Heriot-Watt Univ. , UK), Peter

Claisse (Coventry Univ., UK), Edward Garboczi (NIST, USA), F. de Larrard (LCPC,

France), Nicos Martys (NIST, USA), Walter Rossiter (NIST, USA), T. Sedran (LCPC,

France)

We would also like to thank the members of ACI 236A for their lively discussion during

ACI conventions and their support of this study.
Table of Contents

1. INTRODUCTION............................................................................................................................... 1

2. CONCRETE MIXTURES ................................................................................................................. 4

2.1. CONSTITUENTS ....................................................................................................................... 4

2.2. MIXTURE PROPORTIONS....................................................................................................... 5

2.3. MIXTURE PRODUCTION ...................................................................................................... 11

2.4. MIXTURE MEASUREMENTS ............................................................................................... 11

3. CONCRETE RHEOMETERS ........................................................................................................ 13

3.1. THE BML RHEOMETER........................................................................................................ 13

3.1.1. Description of the apparatus................................................................................................ 13

3.1.2. Analysis of data .................................................................................................................... 14

3.2. BTRHEOM RHEOMETER...................................................................................................... 16

3.2.1. Description of the apparatus................................................................................................ 16

3.2.2. Test procedure ...................................................................................................................... 17

3.2.3. Analysis of the data............................................................................................................... 17

3.3. THE IBB RHEOMETER.......................................................................................................... 19

3.3.1. Description of the apparatus................................................................................................ 19

3.3.2. Analysis of the data............................................................................................................... 20

3.4. THE TWO-POINT RHEOMETER........................................................................................... 22

3.4.1. Description of the apparatus................................................................................................ 22

3.4.2. Test procedure ...................................................................................................................... 22

3.4.3. Analysis of the data............................................................................................................... 23

3.5. UIUC RHEOMETER (USED ONLY FOR OIL TESTS)......................................................... 25

3.5.1. Description of the apparatus................................................................................................ 25

3.5.2. Test procedures..................................................................................................................... 25

4. MEASUREMENTS USING OIL .................................................................................................... 29

4.1. MATERIALS AND PROCEDURE.......................................................................................... 29

4.2. RESULTS AND DISCUSSION................................................................................................ 29

5. RESULTS FOR CONCRETE AND MORTAR MIXTURES ...................................................... 32

6. DISCUSSION OF RESULTS WITH CONCRETE AND MORTAR.......................................... 36

6.1. CORRELATION BETWEEN SINGLE POINT TESTS AND RHEOMETER RESULTS FOR

CONCRETE............................................................................................................................................ 36

6.2. COMPARISON BETWEEN RHEOMETERS ......................................................................... 38

6.2.1. General Trends..................................................................................................................... 38

6.2.2. Comparison of measurements on concrete mixtures ............................................................ 39

6.2.3. Ranking of the concrete mixtures by the various rheometers............................................... 46

6.2.4. Comparison of Results from Phase I (2000) and Phase II (2003) [3].................................. 47

6.3. REPEATABILITY OF DATA.................................................................................................. 51

6.4. RELATIVE VISCOSITY: MORTAR AND CONCRETE....................................................... 54

7. SUMMARY OF FINDINGS ............................................................................................................ 57

8. RESOLUTION OF PHASE I RECOMMENDATIONS AND RECOMMENDATIONS FOR

FUTURE WORK ....................................................................................................................................... 59

8.1. RESOLUTION OF PHASE I RECOMMENDATIONS........................................................... 59

8.2. RECOMMENDATIONS FOR FUTURE WORK .................................................................... 59

9. REFERENCES.................................................................................................................................. 61
List of Figures

Figure 1: The aggregates used in the Cleveland test: Sand and gravel particles. As shown to the

right, the aggregate size can be larger than 25 mm due to elongated shape. ........................ 5

Figure 2: U-Box schematic and dimensions ................................................................................. 12

Figure 3: V-Funnel schematic and dimensions............................................................................. 12

Figure 4. The ConTec BML Viscometer....................................................................................... 13

Figure 5 : To the left: The inner and outer cylinder of the BML. To the right: The computed shear

stress τ (in Pa) for the C-200 system [21]. τo = 200 Pa, μ = 20 Pa⋅s, N = 0.076 rad/s (0.48

rps)........................................................................................................................................ 14

Figure 6: A three-dimensional- and a top view of the coaxial cylinder viscometer...................... 15

Figure 7: Kinematic viscosity of CylEsso 1000 measured with tube viscometer (oil testing

laboratory Fjölver) and the BML. ........................................................................................ 15

Figure 8: The BTRHEOM rheometer showing the blades at the top and bottom of the bucket

containing the concrete [8]. ................................................................................................. 16

Figure 9: Picture of IBB Rheometer ............................................................................................. 19

Figure 10: Picture of portable IBB Rheometer (a) in the lab and (b) on a construction site ....... 20

Figure 11 - IBB Calculation Example. The range of speed are 0 rad/s to 0.15 rad/s................... 21

Figure 12 -a) dimensions for the IBB H impeller; b) dimensions for the IBB portable H impeller

.............................................................................................................................................. 21

Figure 13: Impeller and bowl dimensions (in mm) of the Two-point test .................................... 24

Figure 14: General arrangement of the two-point test ................................................................ 24

Figure 15. Parallel-plate concrete rheometer at UIUC................................................................ 26

Figure 16: Sketch of UIUC rheometer (A) and detailed dimensions of the rheometer (B)........... 27

Figure 17: Reproducibility of rheological measurements using the UIUC rheometer................. 28

Figure 18: Range of Bingham properties measured in tests at MB .............................................. 35

Figure 19: Range of Bingham properties measured in tests at LCPC.......................................... 35

Figure 20: Relationships between yield stress/yield term and slump for concrete mixtures ....... 36

 Figure 21: Relationships between yield stress/yield term and slump flow for concrete mixtures37

Figure 22: Relationships between plastic viscosity/viscosity term and V-funnel flow time for

concrete mixtures.................................................................................................................. 37

Figure 23: Relationships between plastic viscosity/viscosity term and T50 times for concrete

mixtures................................................................................................................................. 37

Figure 24: Plastic viscosity vs. concrete or mortar mixtures. The lines connecting the points are

only used to guide the eye and are not meant as implication of a relationship between the

points. ................................................................................................................................... 38

Figure 25: Yield stress vs. concrete or mortar mixtures. The lines connecting the points are only

used to guide the eye and are not meant as implication of a relationship between the points.

.............................................................................................................................................. 38

Figure 26: Yield stress correlations.............................................................................................. 42

Figure 27: Yield stress correlations (cont) ................................................................................... 43

Figure 28: Plastic viscosity correlations ...................................................................................... 44

Figure 29: Plastic viscosity correlations (cont)............................................................................ 45

Figure 30: Yield tress correlations obtained at LCPC and MB for concrete mixtures................. 49

Figure 31: Plastic viscosity correlations obtained at LCPC and MB for concrete mixtures........ 50

Figure 32: Relative viscosity (using D2M5Mort as a reference) for each rheometer as a function

of the mixture number........................................................................................................... 55
List of Tables

Table 1: Aggregate particle size distributions ................................................................................ 4

Table 2: Mixture proportions and measurements for Day 1 mixtures. See section 2.4 for the

measurements details.............................................................................................................. 8

Table 3: Mixture proportions and measurements for Day 2 mixtures. See section 2.4 for the

measurements details.............................................................................................................. 9

Table 4: Mixture proportions and measurements for Day 3 mixtures. See section 2.4 for the

measurements details............................................................................................................ 10

Table 5: Results with oil using the various rheometers................................................................. 31

Table 6: Results obtained with all mixtures. The mixture # is given to simplify the plot of some

data in graphs....................................................................................................................... 33

Table 7: Correlation coefficients R for yield stress values of concrete mixtures......................... 39

Table 8: Correlation coefficients R for plastic viscosity of concrete mixtures.............................. 39

Table 9: Critical values for the absolute value of the correlation coefficient R of a sample

extracted from a normal distribution. Α is the confidence, and γ = n -2, where n is the

number of points. .................................................................................................................. 40

Table 10: Coefficients of regression A and B for yield stress of concrete mixtures (Y = A X + B)

.............................................................................................................................................. 41

Table 11: Coefficients of regression A and B for plastic viscosity of concrete mixtures (Y = A X +

B) .......................................................................................................................................... 41

Table 12: Ranking of the yield stress of the concrete mixtures as determined by the rheometers.

The mixtures are ranked in increasing order of yield stress from 1 to 15............................ 46

Table 13: Ranking of plastic viscosity of the concrete mixtures as determined by the rheometers.

The mixtures are ranked in increasing order of yield stress from 1 to 13............................ 46

Table 14: Correlation coefficients, R, for yield stress values (MB and LCPC) for the concrete

mixtures................................................................................................................................. 47

Table 15: Correlation coefficients, R, for plastic viscosity (MB and LCPC) for the concrete

mixtures................................................................................................................................. 48

Table 16: Regression coefficients A and B for yield stress (MB and LCPC) for the concrete

mixtures................................................................................................................................. 48

Table 17: Regression coefficients A and B for plastic viscosity (MB and LCPC) for the concrete

mixtures................................................................................................................................. 48

Table 18: Average yield stress for the mixture repeatability. No standard deviation was

calculated when only one value was available..................................................................... 52

Table 19: Average plastic viscosity for the mixture repeatability. No standard deviation was

calculated when only one value was available..................................................................... 52

Table 20: Average for the non-rheometer tests............................................................................. 53

Table 21: Average relative viscosity and coefficient of variation (using D2M5Mort as a

reference).............................................................................................................................. 56

1

1. Introduction

The use of concrete with appropriate rheological properties is paramount for determining

the performance and durability of the material. Rheological properties control the flow of

the concrete in mixing, placement, consolidation and finishing. Typically during a

project, all of these characteristics are referred to as workability and often measured using

only the slump test (ASTM C 143). Unfortunately, this test does not completely define all

the rheological properties of fresh concrete, particularly for specialty concretes such as

self-consolidating concretes (SCC).

It is generally agreed that the flow of a concrete can be usually described using a

Bingham equation. This equation is a linear function of shear stress (the concrete

response) versus shear rate. The general form of this relationship is:

τ = τ +ηγ& 0 [ 1]

where τ is the shear stress and γ& is the shear rate. Two parameters provided by the

Bingham equation are the yield stress, τ0, (y-intercept of the line) and the plastic

viscosity, η (slope of the line). The yield stress is analogous to the amount of shear stress

required to initiate flow whereas the plastic viscosity describes the resistance to flow

once the concrete is flowing. The yield stress correlates reasonably well with the slump

value, but the plastic viscosity does not. The existence of the plastic viscosity helps

explain why concretes with the same slump may behave differently during placement.

In certain instruments, it is not possible to measure the shear stress and shear rate because

the geometry and the flow pattern of the fluid are not correctly known. In this case,

Tattersall [18] was the first to introduce the concept of measuring the torque (related to

the shear stress) and the velocity of rotation of the vane or inner cylinder (related to shear

rate). In a plot of the torque versus the rotational speed, the slope of the linear curve and

the intercept at zero speed are called, respectively, H and G.

To calculate the plastic viscosity value as H or η, the slope of the torque vs. rotational

speed curve or shear stress vs. shear rate curve respectively is calculated by linear

regression. The intercept of the linear regression at zero shear rate or zero rotational

speed is τ0 or G, respectively. The value of linear regression coefficient, R2

 is used to

determine whether the calculations are significant. A value of R2

 close to 1 indicates that

the relationship is adequately described by a straight line. In this report, we will use these

definitions to determine the plastic viscosity and yield stress using various rheometers.

In summary, tests that are more sophisticated than the slump test are needed to determine

the workability or flow properties of concrete mixtures. Several instruments have been

designed to address this problem [4]. Some of these devices rely on empirical

relationships (such as the slump test), while others rely on absolute physical relationships

of the fluid rheology as they apply to concrete materials. The devices designed to use
2

fluid rheology methods to measure the flow of concrete are called rheometers [5]. They

generally measure the torque at varying rotational velocities and might or might not relate

those values to shear stresses and shear rates, respectively.

Rheometers designed for polymers or neat fluids with no solid particles are not suitable

for measuring the flow characteristics of concrete due to the presence and size of the

aggregates. Concrete rheometers have a wide variety of designs to deal with the problem

of measuring the rheological properties of a fluid containing a large volume percent of

solid particles. The range of designs makes it difficult to compare the results from the

rheometers on a common basis. One obvious solution would be to have a standard

reference material to calibrate the rheometers. To date, no standard material has been

developed to simulate fresh concrete rheological behavior. Therefore, the best alternative

for comparing the instruments was to bring the rheometers to one location and conduct

measurements on the same concrete mixtures.

The goal for Phase II of this project was to extend the work of Phase I by comparing the

rheometer measurements on another set of concrete mixtures. Phase I of this project was

conducted in France in 2000 [3]. The results of Phase I were that the rheometers ranked

all the concrete in the same order, but that their absolute values of plastic viscosity and

yield stress are not directly comparable. Preliminary pair wise correlation functions were

developed for the rheometers present at the Phase I testing.

Concrete rheometers that are available today are:

• BML (Iceland) [6, 7]

• BTRHEOM (France) [8, 9]

• CEMAGREF-IMG coaxial rheometer (France) [1]

• IBB (Canada) [10]: two versions: lab and portable

• Two-Point (UK) [11]

• UIUC (USA) [12, 13]

• The Flow of High Performance Concrete Meter (FHPCM) [14]

• Bertta Apparatus [15]

This list might not be complete, but the authors are not aware of others rheometers at this

time.

The CEMAGREF-IMG was not used in the present study because it was not possible to

transport such a large rheometer (500 L capacity) to the Cleveland test site. The UIUC

rheometer was not present in Cleveland due to logistic reasons, but it was used for the oil

measurements that are reported here. The last two rheometers listed were not available

for this study.

The IBB and Two-Point rheometers are based on rotating an impeller in fresh concrete

contained within a cylindrical vessel. The shape of the impeller varies with the

rheometer. The BTRHEOM and UIUC are parallel plate rheometers. The concrete is

placed in a cylindrical container with a fixed bottom plate and a rotating upper plate. The

CEMAGREF-IMG and the BML are coaxial cylinder rheometers in which one cylinder

(inner cylinder for the CEMAGREF-IMG and outer for the BML) is rotated at controlled
3

speed. For all the rheometers, the standard procedure is to increase and then decrease the

speed of the rotating arm (vane, top plate or inner/outer cylinder) and to measure the

torque resulting from the concrete. The flow pattern of the concrete in the IBB and TwoPoint rheometers cannot be easily assessed or modeled, while the flow can be

mathematically modeled for the coaxial rheometers (BML, CEMAGREF-IMG) and for

the parallel-plate rheometers (BTRHEOM, UIUC). For these four rheometers (BML,

BTRHEOM, CEMAGREF-IMG, UIUC), rheological characteristics in fundamental units

can be estimated from the mathematical model of the flow geometry. Test results for

these four rheometers are reported here in fundamental units (shear stress = Pascals (Pa);

viscosity = Pascal seconds (Pa⋅s). The Two-Point rheometer used in this test was

calibrated to convert its torque/speed raw data into fundamental units using calibrating

fluids of known viscosity. The IBB rheometer can also be calibrated to convert

torque/speed data into fundamental units. However, the instruments used in this test were

not calibrated and therefore, the IBB results are not reported in fundamental units.

Comparison and correlation functions, which can relate the results obtained with the

various rheometers, are essential to advance the science of concrete rheology and

therefore provide a better characterization of concrete “workability”.

A tentative approach to developing a standard material for concrete rheometers was made

using high viscosity oil. This oil can be accurately measured in a laboratory fluid

rheometer and concrete rheometers could be calibrated by measuring the oil and

comparing this measurement to the fluid rheometer value. This is only an approximation

at best because the oil is a Newtonian fluid while most concrete is typically assumed to

behave as a Bingham fluid. Also, the concrete has particulates and the oil does not.

Therefore, only viscosity can be compared and not yield stress.

Under the auspices of ACI subcommittee 236A, “Workability of Fresh Concrete,” a

group of researchers obtained a grant from ACI’s Concrete Research Council (CRC) to

conduct a series of comparison tests on concrete rheometers. The first test was conducted

on October 23-27, 2000, in the facilities of the Laboratoire Central des Ponts et

Chaussées (LCPC) located in Nantes (France). An extension of the grant allowed a

second series of tests to be conducted at Masters Builders in Cleveland (Ohio) USA in

May 19-23, 2003.

This report summarizes the rheometers used and their operation, the concrete

compositions and preparation procedure, and all the data obtained as well as some data

interpretation. As in the first report, all the data are presented as measured. This will

provide a valuable database for use by researchers in this field. Summaries of the

different aspects of this research along with further analysis will be presented in ACI

journals and other publications.
4

2. Concrete Mixtures

2.1. Constituents

Twenty-two mixtures (17 concrete and 5 mortar) were produced using cement and

aggregate materials stocked as normal laboratory supply in Master Builder’s Cleveland

Technical Center. All admixtures were commercially available products. All

cementitious, aggregate and admixture materials used throughout the testing were taken

from the same lots.

The cement was an ASTM Type I/II from Ashgrove Cement Company. The fly ash was a

Class F ash from ISG. The dry condensed silica fume was Rheomac SF 100. A

polycarboxylate-based admixture (commercial name: Glenium 3030) was used in all

mixtures requiring a high-range water-reducer admixture (HRWRA). The air-entraining

admixture (AEA) used in mixture D1M5Conc was Micro-Air and the viscositymodifying admixture (VMA) used in mixtures D2M3Conc and D2M7Conc was

Rheomac VMA 450.

Three different aggregate fractions were used in each concrete mixture. Only the fine

aggregate fraction was used in the five mortar mixtures. The fine aggregate fraction was

quarried natural sand with angular shaped grains. The two coarse aggregate fractions

were different gradings of a crushed limestone material. The size distributions of the

three aggregate fractions are given in Table 1. The coarse aggregate absorption was

0.6 % by mass fraction and the bulk saturated-surface-dry specific gravity was 2.78. The

fine aggregate absorption was 1.79 % and the bulk saturated-surface-dry specific gravity

was 2.58.

Table 1: Aggregate particle size distributions

US

Standard

Sieve

Mesh Size

[μm]

Cumulative %

Retain

CoarseAgg1

#57

Cumulative %

Retain

CoarseAgg2

#8

Cumulative %

Retain

Fine

Aggregate

1 in. 25000 0.1

3/4 in. 19000 16.8

1/2 in. 12500 74

3/8 in 9500 84.2 9.3

#4 4750 96.2 71.2 0.4

#8 2360 98.6 93.7 11.2

#16 1180 98.6 97.8 26.6

#30 600 46.5

#50 300 78.3

#100 150 95.8

#200 75 98.7

Pan 100 99.7 99.8
5

As is shown in Figure 1, the coarse aggregate fraction contains particles with some

dimensions larger than nominal 25 mm. There was no attempt made in this test program

to provide a carefully designed aggregate gradation for each concrete as was the case in

the Phase I tests. The aggregate gradation used for these tests was selected first to be

constant over all tests and second to be representative of common US proportioning

practice. However, as described below, a decision was made during the actual testing to

modify the aggregate gradation for preparation of the LoYld baseline concrete and related

test mixtures. Originally it was intended to use the constant sand to total aggregate

volumetric ratio (S/A) of 0.50 for all mixtures. This was changed during testing to

provide a 0.55 S/A for the LoYld related test mixtures.

Figure 1: The aggregates used in the Cleveland test: Sand and gravel particles. As

shown to the right, the aggregate size can be larger than 25 mm due to elongated

shape.

2.2. Mixture Proportions

The objective was to prepare all test mixtures as variations of two baseline concrete

mixtures. One baseline mixture (HiYld) was a conventional concrete proportioned to

provide a slump of 100 mm to 150 mm. The primary objective for the HiYld baseline

mixture was a uniform reproducible concrete with a slump value not less than 100 mm.

The other baseline mixture (LoYld) was a self-consolidating concrete (SCC)

proportioned to provide a slump flow of 550 mm to 650 mm. The primary objective for

the LoYld baseline mixture was a uniform reproducible highly fluid concrete with no

segregation.

Each of the baseline mixtures (HiYld and LoYld) was mixed and tested three times to

provide reproducibility data. In addition, baseline mortar mixtures were prepared from

each baseline concrete mixture proportion by removing the coarse aggregate fraction. The

HiYld baseline mortar was prepared three times and the LoYld mortar was prepared one

time.
6

The list of the mixtures is shown below. The name code is DXMYConc or DXMYMort

where DX indicates the day of mixing (e.g. D2 = day 2), and MY indicates the mixing

order on a specific day (e.g. M3 = mixture 3). Conc designates a concrete mixture while

Mort designates a mortar mixture (coarse aggregate fraction omitted).

The test mixtures derived from the HiYld baseline were as follows:

Mixture ID Description

D1M1Conc first HiYld baseline concrete mixture

D1M1Mort first HiYld baseline mortar mixture

D1M2Conc second HiYld baseline concrete mixture

D1M2Mort second HiYld baseline mortar mixture

D1M3Conc HiYld baseline concrete mixture VARIATION add water

D1M4Conc HiYld baseline concrete mixture VARIATION add HRWRA

D1M5Conc HiYld baseline concrete mixture VARIATION add AEA

D2M1Conc third HiYld baseline concrete mixture

D2M1Mort third HiYld baseline mortar mixture

D3M4Conc HiYld baseline concrete mixture VARIATION add fly ash

The test mixtures using the LoYld baseline were as follows:

Mixture ID Description

D2M4Conc first LoYld baseline concrete mixture

D2M5Conc second LoYld baseline concrete mixture

D2M6Mort correct LoYld baseline mortar

D2M7Conc LoYld baseline concrete mixture VARIATION add VMA

D3M2Conc LoYld baseline concrete mixture VARIATION add fly ash

D3M3Conc LoYld baseline concrete mixture VARIATION add silica fume (1)

D3M5Conc third LoYld baseline concrete mixture

D3M6Conc LoYld baseline concrete mixture VARIATION add silica fume (2)

An additional three concrete mixtures and one mortar were prepared that did not use

either the HiYld or LoYld baseline mixture proportions.

• D2M5Mort was to be the baseline mortar mixture for D2M5Conc however the

HRWRA was incorrectly dosed. The mixture was completely measured and

retained to provide an additional data point.

• D2M2Conc was the initially planned mixture proportions for the LoYld baseline.

This concrete was judged to be too close to segregation to be used as the baseline

mixture for the LoYld mixture series. The mixture proportions were changed to

decrease the water-cementitious materials ratio (w/cm) and increase the sand-total

aggregate ratio (S/A). These revised LoYld baseline mixture proportions were

tested as D2M4Conc and selected as the LoYld baseline mixture listed above.

• D2M3Conc was the same mixture proportions as D2M2Conc but with addition of

VMA.

• D3M1Conc was an additional concrete mixture prepared with the same w/cm as

the LoYld baseline but with increased S/A.
7

Table 2 to Table 4 show the mixture proportions and laboratory measurements for each

mixture in order as prepared for each test day. Note that the dosage of the admixtures was

calculated on the basis of mass of active admixture solids to mass of the cement only

even if supplementary cementitious materials were present.
8

Table 2: Mixture proportions and measurements for Day 1 mixtures. See section 2.4

for the measurements details.

Mixture ID D1M1

Conc

D1M1

Mort

D1M2

Conc

D1M2

Mort

D1M3

Conc

D1M4

Conc

D1M5

Conc

Mixture design kg/m3 kg/m3 kg/m3 kg/m3 kg/m3 kg/m3 kg/m3

Cement 413 613 407 614 416 402 389

Silica Fume 0000000

Fly Ash 0 0 0 0 0 0 0

Fine Agg. (SSD) 869 1292 857 1294 834 846 819

Coarse Agg1

(SSD) (#57)

608 0 599 0 584 573 573

Coarse Agg2

(SDD) (#8)

327 0 323 0 314 318 308

Total Water 186 276 183 276 197 180 175

w/cm 0.45 0.45 0.45 0.45 0.47 0.45 0.45

S/A 0.50 1.00 0.50 1.00 0.50 0.50 0.50

Coarse Agg. Vol.

 Fraction [%] 54.7 0.0 54.7 0.0 52.6 53.6 54.7

Admixtures

HRWRA (% by

mass fract cement)

0.04

VMA (% by mass

fract. of cement)

AEA (% by mass

fract. of cement)

0.005

Measurements

∆t (min) 19 15 9 14 12 33 10

Density (kg/m3) 2402 2179 2371 2185 2345 2339 2262

Gravimetric Air

(%)

1.0 3.0 2.4 2.7 2.6 3.7 6.8

Pressure Air (%) 1.6 1.4 1.4 0.9 0.9 2.6 6.1

Concrete

Temperature (°C)

24 24 24 24 24 24 24

Slump (mm) 152 127 248 210 210 133

Slump Flow (mm) 483

U-box Rise Ht

(mm)

184 375 235 387 394 260 216

V-funnel Time (s) 2.0 1.9 4.0 6.5

Note: The value of ∆t for each mixture was the elapsed time in minutes from the contact

of water and cement until the start of all measurement procedures.
9

Table 3: Mixture proportions and measurements for Day 2 mixtures. See section 2.4

for the measurements details.

Mixture ID D2M1

Conc

D2M1

Mort

D2M2

Conc

D2M3

Conc

D2M4

Conc

D2M5

Conc

D2M5

Mort

D2M6

Mort

D2M7

Conc

Mixture Design kg/m3 kg/m3 kg/m3 kg/m3 kg/m3 kg/m3 kg/m3 kg/m3 kg/m3

Cement 412 625 438 443 480 478 686 691 492

Silica Fume 000000000

Fly Ash 0 0 0 0 0 0 0 0 0

Fine Agg. (SSD) 868 1316 851 883 926 922 1322 1331 949

Coarse Agg1

(SSD) (#57)

606 0 596 618 530 528 0 0 543

Coarse Agg2

(SDD) (#8)

326 0 321 333 285 284 0 0 292

Total Water 185 281 175 160 166 165 237 238 170

w/cm 0.45 0.45 0.40 0.36 0.35 0.35 0.35 0.35 0.35

S/A 0.50 1.00 0.50 0.50 0.55 0.55 1.00 1.00 0.55

Coarse Agg. Vol.

Fraction [%] 54.7 0.0 54.5 56.6 46.1 46.1 0.0 0.0 46.0

Admixtures

HRWRA (% by

mass fract cement)

0.13 0.26 0.2 0.2 0.13 0.2 0.25

VMA (% by mass

fract. of cement)

0.02 0.02

AEA (% by mass

fract. of cement)

Measurements

∆t (min) 14 16 44 26 26 15 17 19 18

Density (kg/m3) 2396 2224 2383 2434 2383 2377 2243 2262 2447

Gravimetric Air

(%)

1.3 1.0 2.6 1.7 3.2 3.4 3.4 2.6 0.6

Pressure Air (%) 1.3 1.2 1.9 0.9 3.2 3.2 4.0 1.6 0.6

Concrete

Temperature (°C)

24 24 24 23 23 23 23 23 23

Slump (mm) 121 241

Slump Flow (mm) 457 660 641 635 533 444 787 610

T50 (s) 2.0 4.7 2.3 4.7 2.8

U-boxRiseHt

(mm)

184 343 349 362 356 349 324 362 349

V-funnel Time (s) 2.3 2.9 9.2 5.8 7.3 3.1 1.9 8.9

Note: The value of ∆t for each mixture was the elapsed time in minutes from the contact

of water and cement until the start of all measurement procedures.
10

Table 4: Mixture proportions and measurements for Day 3 mixtures. See section 2.4

for the measurements details.

Mixture ID D3M1

Conc

D3M2

Conc

D3M3

Conc

D3M4

Conc

D3M5

Conc

D3M6

Conc

Mixture Design kg/m3 kg/m3 kg/m3 kg/m3 kg/m3 kg/m3

Cement 479 367 428 320 481 450

Silica Fume 0 0 37 0 0 18

Fly Ash 0 92 0 80 0 0

Fine Agg. (SSD) 1097 940 917 882 927 920

Coarse Agg1

(SSD) (#57)

387 538 524 616 531 527

Coarse Agg2

(SDD) (#8)

208 289 282 332 285 283

Total Water 166 168 164 188 166 165

w/cm 0.35 0.37 0.35 0.47 0.35 0.35

S/A 0.67 0.55 0.55 0.50 0.55 0.55

Coarse Agg. Vol.

Fraction [%] 30.7 45.8 45.9 54.3 46.1 46.1

Admixtures

HRWRA (% by

mass fract cement)

0.2 0.22 0.22 0.2 0.21

VMA (% by mass

fract. of cement)

AEA (% by mass

fract. of cement)

Measurements

∆t (min) 16 24 11 12 11 11

Density (kg/m3) 2337 2396 2350 2416 2389 2363

Gravimetric Air

(%)

4.3 1.5 3.9 0.0 2.9 3.6

Pressure Air (%) 4.0 1.1 4.2 0.9 2.2 4.3

Concrete

Temperature (°C)

23 23 23 23 23 23

Slump (mm) 222 222 203 241

Slump Flow (mm) 356 622 356 356 597 406

T50 (s) 1.4 2.2

U-box Rise Ht

(mm)

292 362 305 292 349 311

V-funnel Time (s) 6.4 2.4 8.4 3.2 5.2 7.8

Note: The value of ∆t for each mixture was the elapsed time in minutes from the contact

of water and cement until the start of all measurement procedures.
11

2.3. Mixture Production

All mixtures prepared over the three days of testing were mixed in the same rotating

drum mixer (capacity 170 L). The same mixing procedure was followed for all concrete

mixtures. The mixer was charged with approximately three-quarters of the mixing water,

and all the coarse aggregate, cement and sand. The mixer and time clock were started.

The remaining mixing water was added within the first minute of mixing. Mixing was

continued at a constant 2.09 rad/s (20 rpm) drum rotation rate for a total of 5 min. After 5

min mixing, the concrete was discharged into two wheelbarrows and moved closer to the

various rheometers located throughout the laboratory. Each rheometer crew transferred

concrete using hand scoops to fill the rheometer from the wheelbarrows and signaled

their readiness to start. When all groups were ready a start-command was given and all

testing started at the same time.

The mixing procedure was changed for the mortar mixtures. All cement and sand were

charged and the mixer was started. After approximately 30 s to 60 s of dry mixing, the

clock was started and the mixing water was gradually added with the mixer turning. Total

mixing time from addition of first water was 5 min. The mixer was discharged into

wheelbarrows and from there followed the same sequence as the concrete mixtures.

Addition of admixtures was varied according to admixture type. Air-entraining admixture

for D1M5Conc was added at the start of mixing. Viscosity-modifying admixture for

D2M3Conc and D2M7Conc was added after 2 min of mixing. HRWRA for all mixtures

was added with approximately 80 % of total dosage in the initial charge water and the

remainder added to the mixture before completion of 2 min of mixing.

2.4. Mixture Measurements

Each concrete or mortar mixture prepared during the three test days was measured using

some or all of the following methods in addition to the measurements made by the

concrete rheometers. These measurements are recorded in the measurements section of

Table 2 to Table 4. Each concrete rheometer was used to determine the yield stress and

plastic viscosity characteristics of each concrete and mortar mixture using the Bingham

relationship. The results of these tests are presented in Chapter 5.

The value of ∆t for each mixture was the elapsed time in minutes from the contact of

water and cement until the start of all measurement procedures. Gravimetric air content

and density were determined for all mixtures according to ASTM C 138. Pressure air

content was determined for all mixtures according to ASTM C 231. Temperature for each

mixture was measured using the same thermometer inserted into the concrete in one of

the distribution wheelbarrows.

Slump and/or slump flow measurements were made on each mixture. Slump was

measured according to ASTM C 143 with the measurement frustrum centered on a

smooth, level polymer surface. Slump flow was measured as the average of the maximum
12

and minimum diameters of the pile remaining after making the standard slump

measurement.

Mixtures were measured for rising height (UboxRiseHt) using a stainless steel U-box

having internal dimensions as shown in Figure 2. The dimension of the U-box in this

study is identical to those used by PCI [16] and JSCE [17]. V-funnel times (V-funnel

Time) were measured for all mixtures with slump greater than 200 mm. The V-funnel

used was a stainless steel apparatus having internal dimensions as shown in Figure 3.

Figure 2: U-Box schematic and dimensions

Figure 3: V-Funnel schematic and dimensions

280

200 

130 130 

Plan view of top cross-section

680 

280

moving door 190 

dimensions in mm

280

200 

130 130 

Plan view of top cross-section

680 

280

moving door 190 

dimensions in mm

Top view

dimensions in mm

Front view

475

76

76

152

Top view

dimensions in mm

Front view

475

76

76

152
13

3. Concrete Rheometers

3.1. The BML Rheometer

3.1.1. Description of the apparatus

The ConTec BML Viscometer 3, used in this test, is a coaxial cylinder viscometer for

coarse particle suspensions. It is based on the Couette viscometer [18] principle where

the inner cylinder measures torque as the outer cylinder rotates at variable angular

velocity. It was developed in Norway in 1987 [19, 20] after six years of intensive work

with the Tattersall Two-point test instrument. For the tests described in this report, the

ConTec BML Viscometer 3 was used (Figure 4). To simplify the text, this instrument

will be referred simply as BML in the rest of this report.

Figure 4. The ConTec BML Viscometer

The instrument is fully automated and is controlled by computer software called

FreshWin. Each test takes about 3 min to 5 min, from filling the bowl/material container

to emptying it. During testing, the material is exposed to shear for about one minute

(depending of the software set-up used). A trolley is used for transporting the container

(outer cylinder) full of concrete for easy operation.

Several measuring systems can be used depending on the maximum aggregate size in the

suspension to be tested. Details are given in Ref. [3]. Each measuring system is related to

the diameter of the inner cylinder. The C-200 measuring system was used in the

comparison tests in both rheometer comparison tests held in Nantes [3] and the present

test series. This system assumes that the maximum aggregate size is 16 mm. In the

Cleveland test, it was about 25 mm, which is higher than assumed for the current

geometry.
14

The parameters for each measuring system are incorporated as a standard set-up in the

FreshWin software. Details of the measurements are given in Ref. [3].

Figure 5 shows the inner and outer cylinder. Both cylinders contain ribs parallel to their

axis. Therefore, it is the material tested that will form the actual inner and outer cylinder.

This leads to a larger cohesion (or stickiness) between the cylinders and the test material,

hence reducing the danger of slippage.

1 61 107 240 306

1

29

101

146

j−direction (z)

i−direction (r)

100

150

200

300

350

400 Ω 450

Ωe p

Figure 5 : To the left: The inner and outer cylinder of the BML. To the right: The

computed shear stress τ (in Pa) for the C-200 system [21]. τo = 200 Pa, μ = 20 Pa⋅s, N =

0.076 rad/s (0.48 rps).

The inner cylinder consists of three parts; the upper unit (measuring unit), the lower unit

and the top-ring (Figure 5). It is only the upper unit that measures torque. The lower unit

is to eliminate or minimize the so-called bottom effects. In this way it is insured that only

two-dimensional shearing of the test material generates torque, which the instrument

records. The functionality of the top ring is somewhat less important. Its main function is

to keep a constant height h where torque is measured. This is done to simplify the

calculations of the plastic viscosity μ and the yield value τo. If omitted, then the height

has to be measured for each test and put manually in the Fresh Win software.

As shown in Figure 5, at the bottom of the coaxial cylinder viscometer a complex threedimensional shearing occurs in the material. In this bottom zone, the shear rate is not

uniform for the given angular velocity. In addition, the material may not have reached

equilibrium shear stress for the given angular velocity, although it has done so at the

upper zone where the pre-mentioned two-dimensional shearing exists.

3.1.2. Analysis of data

As for all of the rheometers used in this test program, the results are interpreted using the

Bingham model. A three-dimensional and a top view of the coaxial cylinders viscometer

are shown in Figure 6. The outer cylinder (with radius or ) rotates at rotational frequency

N, while the inner cylinder (with radius ir ) is stationary and registers the applied torque T

from the test material (i.e. from the cement-based material). The term h is the height of
15

the inner cylinder. Equation (2) relates H and G to μ and the yield value o τ of the tested

material Further description about this equation can for example be found in [3].

[ 2]

Further details and discussion on this instrument could be found in ref. [18, 21, 22, 3].

Figure 6: A three-dimensional- and a top view of the coaxial cylinder viscometer.

Calibration of the torque and the angular velocity is done by external load cell and

stopwatch (or light-tacho meter). The measured values are inserted into the FreshWin

software, which calculates the calibration constants. To confirm that the calibration is

correct one can test commercial products with known or stable rheological properties,

like the oil, CylEsso 1000. Figure 7 shows theoretical line and measured kinematic

viscosity with the BML Viscometer (Borregaard & Euroc Res.) and values measured

with a tube viscometer by the oil-testing laboratory Fjölver. The results show good

correlation and indicate that the BML Viscometer (due to the high accuracy of the

instrument) can also be used to measure the viscosity of such a fluid liquid as the CylEsso

1000.

Figure 7: Kinematic viscosity of CylEsso 1000 measured with tube viscometer (oil

testing laboratory Fjölver) and the BML.
16

3.2. BTRHEOM Rheometer

3.2.1. Description of the apparatus

The BTRHEOM rheometer (Figure 8) is a parallel plate rheometer capable of measuring

the flow properties of moderately to highly fluid concrete mixtures; namely, those with

slumps greater than approximately 100 mm (4 in). The device consists of a 240 mm

diameter cylindrical container with two parallel blades mounted at the top and bottom of

the container a vertical distance of 100 mm apart. The bottom blade remains stationary

as the top blade rotates, resulting in the application of shear stress to the concrete

specimen. The motor is housed below the container and is connected to the top blade

through a 40 mm diameter shaft that extends through the center of the container. The

resultant torque from the top blade is measured as this top blade is rotated at a series of

different rotation speeds. The device includes a vibrator to consolidate the concrete and

to measure the effect of vibration on rheological parameters.

An accompanying software program, ADRHEO, operates the device, records data, and

computes the rheological parameters. The text output file includes the computed

rheological parameters and the values of torque for each rotation speed. Different

versions of ADRHEO are available to either calculate the Bingham parameters or the

Herschel-Bulkley parameters.

A more complete description of the device, including details on the derivation of the

Bingham parameters and the Herschel-Bulkley parameters, is available in the report from

the previous comparison of concrete rheometers [3]. Additional information on the

development and implementation of the device is available in Refs. [23], [24], and [25].

Figure 8: The BTRHEOM rheometer showing the blades at the top and bottom of the

bucket containing the concrete [8].
17

3.2.2. Test procedure

Prior to initial testing, the BTRHEOM rheometer was calibrated for torque, rotational

velocity, and vibration frequency as per the manufacturers’ specifications. Before each

test, further refinement of calibration was completed by performing a rotational

calibration test. Two seals, used to prevent concrete from penetrating into the area

between the bucket and rotating cylinder, were carefully fitted to the apparatus before

each mixture was tested. To account for the frictional resistance of each set of seals, a

rheology test was completed with water. The results are used by the ADRHEO software

to account for the mean friction effects of the seals for the following test with concrete or

mortar mixtures.

The procedures used for testing were developed to closely mimic those used in the pilot

study in Nantes, France [3]. A description of the general procedures is given. Notes

attached to individual mixtures in Appendix A are provided where protocol differed. As

the concrete or mortar was added to the rheometer, the bucket was shaken and the

concrete was rodded as needed to ensure proper filling of the container. High yield stress

(HiYld series) concrete mixtures were pre-vibrated for 15 s at 36 Hz to ensure proper

consolidation. No pre-vibration was used for low yield stress (LoYld series) concrete

mixtures and mortar mixtures. As the tests are performed using the BTRHEOM

rheometer, the ADRHEO software plots the measured torque for the specified varying

rotational velocities after the velocity and reading are stabilized (about 20 s). The tests

consisted of two consecutive down ramps (i.e. decreasing the rotational velocity during

the test) with seven points per ramp and angular velocities ranging from 1.2 rad/s to

0.015 rad/s (0.8 rev/s to 0.1 rev/s). Only the set of results from the first down ramp are

used in the analysis for this study. It is noted that the second series of data points

typically yielded a lower yield stress and similar viscosity when compared to the first

series. The second set of data was obtained for possible future study. It was realized

during the testing that the BTRHEOM lacked capabilities to sufficiently move the

concrete at 0.015 rad/s (0.1 rev/sec) so the analysis was completed for all the mixtures

without that data point. Although some highly fluid concrete and mortar mixtures did

result in reasonable torque values at the low angular velocity (0.015 rad/s or 0.1 rev/s),

the data point was excluded in all mixtures for consistency and to eliminate the

possibility of using any improper outliers points for analysis.

3.2.3. Analysis of the data

Torque versus rotational velocity data is collected with the ADRHEO software.

Although the focus of this study is to obtain the Bingham parameters, the ADRHEO

software has capabilities to report the Hershel-Buckley parameters as well. A straight

line with an intercept (G) in N·m and slope (H) in N·m·s is characteristic of the torque

(N·m) versus rotational velocity (rad/s or rev/s) data for Bingham fluids. Refer to [1] for

a description of the methods to convert the intercept (G) and slope (H) to shear stress and

viscosity respectively. The multipliers to convert G to yield stress and H to plastic

viscosity are 277.596 Pa/N·m and 44.01 Pa·s/N·m·s for this set-up, respectively.
18

The regression analysis and mean friction values for the seal tests were computed and

outputted from the ADRHEO software. The mean friction values were used inherently as

a point of reference for the subsequent concrete and mortar tests. Although the program

has capabilities to complete the regression analysis and report shear stress and viscosity

values, the MS Excel computer program was used to analyze the raw test data for the

concrete and mortar mixtures. This was necessary because of the outliers data points

described above (at the low rotational velocities). In addition, the program will report

regression values for the Herschel-Buckley model if it produces a better fit than the

Bingham model; the focus of this project was to study the Bingham parameters.
19

3.3. The IBB Rheometer

3.3.1. Description of the apparatus

This apparatus is an instrumented and automated version of the existing apparatus

(MKIII) developed by Tattersall [26]. It was modified in Canada by Beaupré [27] to

study the behavior of high performance wet-process shotcrete. The apparatus is fully

automated and uses a data acquisition system to drive an impeller rotating in fresh

concrete. The test parameters are easy to modify in order to produce any required test

sequence. The analysis of the results is also automated and the parameters, G (in Nm) and

H (in N·m·s), related to the Bingham parameters, the yield stress and plastic viscosity, are

displayed on the screen. The user may also retrieve the individual data sets to plot the

flow curves manually.

This apparatus can be used to test concrete with slumps ranging from 40 mm to 300 mm.

It has been successfully used for self-compacting concrete, high-performance concrete,

pumped concrete, dry and wet-process shotcrete, fiber reinforced concrete and normal

concrete. It has also been used on a few job sites as a means of quality control. The

general view of the apparatus is shown in Figure 9. The impeller shape and the planetary

motion are as developed for the Tattersall MKIII (LM) apparatus. The concrete bowl

leaves a 50 mm gap between the impeller and the bowl. The recommended maximum

size aggregate is 25 mm. The sample size is 21 L.

Figure 9: Picture of IBB Rheometer

The IBB Portable rheometer (Figure 10) is a traditional IBB rheometer transformed to be

portable and be used on construction sites. The only difference is the frame. The control
20

system, the planetary motion, impeller and bowl dimension are exactly the same as the

non-portable. On construction sites, it is powered by a portable gas generator.

Figure 10: Picture of portable IBB Rheometer (a) in the lab and (b) on a construction

site

3.3.2. Analysis of the data

The IBB rheometer is fully automated and the results are displayed automatically after a

test is conducted. Different test sequences can be entered into the computer. The stored

measured data of impeller speed and measured torque that are used to calculate G and H,

are displayed on the control unit screen. The software provided with the IBB rheometer

calculates the following parameters from the torque/speed data: H, G, M, B and R2

.

Figure 11 shows the definitions of these parameters. H and G could be related to plastic

viscosity and yield stress, respectively. The first point and the points for which the speed

is 0 are not used in the calculations.

Two sequences were used to conduct the tests during the Cleveland comparison tests: the

normal sequence and the SCC sequence. The first test is normally used for regular

concrete; the maximum impeller speed reached is about 0.15 rad/s (1 rev/s). The second

test used for SCC uses a lower maximum impeller speed of about 0.95 rad/s (0.6 rev/s) to

minimize the risk of segregation.
21

Figure 11 - IBB Calculation Example. The range of speed are 0 rad/s to 0.15 rad/s

3.3.2.1.Differences in H impeller

During the MB tests, a small difference between the two H impellers was noticed. The

Figure 12 shows the exact measurements for the two impellers. The surface area is

related to the induced torque and should lead to a small difference in the measured yield

stress and plastic viscosity.

The H impeller area is 3717.1 mm2

 for the IBB and 4002.3 mm2 for the IBB portable - a

difference of 7 %

a) 

136.2 

117.0 

100.0 9.6 

9.6 

9.6 

Concrete level 

70.2 

[mm] 

b) 

139.0 

119.8 

100.0 11.0 

11.0 

9.6 

Concrete level 

69.5 

[mm] 

Figure 12 -a) dimensions for the IBB H impeller; b) dimensions for the IBB portable

H impeller

0

0,3

0,5

0,8

1

0 6 13 19 25

Speed (rev/s)

Torque (Nm)

1

H

y = Mx+b

y = 0.11x - 0.68

R2 = 0.98

M = 1/H

G = -b/M
22

3.4. The Two-Point Rheometer

3.4.1. Description of the apparatus

The Two-point workability test was identical to that used in the first comparative test

program at LCPC Nantes [3]. It is based on the apparatus first described by Tattersall

and Bloomer [28], with updating of instrumentation, data recording and analysis

procedures. It is fully described in Domone, Xu and Banfill [29].

The principle is that an impeller which imparts a stirring action is rotated in a bowl of

concrete, and driving torque (T) is measured. As stated in the Introduction (section 1), G

and H are calculated from the measurements. Calibration of this instrument with fluids of

known properties has determined the relationships between G and τ0, and H and μ, and

hence τ0 and μ in fundamental units can be obtained.

Two impeller systems are available:

• An axial impeller with four angled blades set in a helical pattern around a central

shaft, which imparts both a stirring and mixing action to the concrete (the MH

system). Only the MH system was used for this report

• An offset H-impeller with a planetary motion through the concrete (the LM

system)

The former, which is suitable for concrete with slump values in excess of about 100 mm,

was used in the current program. Dimensions of the impeller and bowl are given in

Figure 13.

3.4.2. Test procedure

The impeller is driven by a variable speed hydraulic drive unit motor through a gearbox;

the overall arrangement is shown in Figure 14. Torque is measured indirectly through the

oil pressure in the drive unit, with the relationship between the oil pressure and torque

obtained by prior calibration with a plummer block, radius arm and spring balance system

fully described elsewhere [18].

During testing, the oil pressure can be observed on a pressure gauge, or captured digitally

on a PC via a pressure transducer fitted to a tapping in the drive unit casing. The impeller

speed is similarly captured from a tachometer fitted to the drive shaft. Speed is

controlled manually.

The torque/impeller speed relationship was obtained in a single downward sweep of the

speed from 0.15 rad/s to 0.015 rad/s (1 rev/s to 0.1 rev/s) in about 30 s. A guide trace on

the PC screen was used to ensure consistency between tests. The voltages corresponding

to speed and pressure were recorded four times per second, giving approximately 120

data points per test. As well as testing with the impeller rotating in the concrete, it is

necessary to record the oil pressure with the impeller rotating in air (called the idling test)
23

over a similar speed range. The net pressure between the idling and concrete test then

gives the torque needed to rotate the impeller in the concrete.

The calibration to determine the relationships needed to convert G and H to τ0 and μ was

carried out using a high viscosity silicone, a Newtonian fluid, and aqueous solutions of

carboxy methyl cellulose, power law fluids. The calibration theory is described in full in

Chapter 7 of Ref. [18], and the principles were summarized in the report of the first

comparative test program [3].

The resulting relationships are

τ0 = 122*g; μ = 17.24*h [ 3]

The units are:

τ0 is in Pa while g is Nm and the constant is in Pa/N·m

μ is in Pa·s while h is in Nm.s and the constant is in Pa·s/N·m·s

The test procedure for a measurement was as follows.

• The machine was run with the impeller rotating for at least half an hour before

testing to allow the oil to reach equilibrium temperature.

• An idling test was carried out

• The concrete was loaded into the bowl with the impeller rotating at about 0.031

rad/s (0.2 rev/s) until the impeller blades were completely immersed in concrete

• The speed was increased to 0.15 rad/s (1 rev/s), and the data recording is then

started and continued while reducing the speed to zero over about 30 s.

• The impeller was disconnected and the idling test repeated.

3.4.3. Analysis of the data

The data in the form of voltages proportional to speed and torque were recorded directly

into an Excel spreadsheet. After discarding the tail of data at either end of the test, the

following procedure was used for the concrete test data to eliminate the falsely high

pressure kicks that can arise from aggregate particles trapping and interlocking:

• A best fit relationship between pressure and speed was obtained by linear

regression

• The standard deviation of the residuals between the measured and predicted

values was calculated

• Data points that were more than twice the standard deviation from the predicted

value, were substituted by the predicted value and a second 'corrected' regression

line obtained.

In practice, this increases the correlation coefficient of the regression line, but does not

significantly alter the slope and intercept.

The slope and intercept were also obtained for each of the two idling tests and averaged.

The two regression equations were then converted from voltages to oil pressure and

impeller speed and the net pressure/speed relationship (equation 1) obtained by
24

subtraction. The resulting values of G and H were converted into yield stress and plastic

viscosity using equations (3).

Figure 13: Impeller and bowl dimensions (in mm) of the Two-point test

 Figure 14: General arrangement of the two-point test
25

3.5. UIUC Rheometer (Used only for Oil Tests)

3.5.1. Description of the apparatus

This rheometer could not be transported to Cleveland for logistic reasons. Nevertheless,

as oil could be shipped to UIUC, oil tests were performed. The UIUC concrete

rheometer (Figure 15) was built in the machine shop at the University of Illinois at

Urbana-Champaign (UIUC) [12] by modifying the frame of the Two-point Test.

The design of this rheometer was based on the BTHREOM, with major changes to reduce

the difficulties involved in the installation and cleaning of the apparatus during the

experiments. It can be idealized as a pseudo parallel-plate rheometer with additional

sidewalls. The radius of the rotating plate is about 120 mm and the gap between two

shear plates is about 90 mm. The rotational speed of the rheometer is measured by a

calibrated light sensor and digital counter. The torque imposed on the rheometer is

measured by a rotatory torque transducer. A PMac 2000 digital data acquisition device,

manufactured by Sensor Developments Inc., was utilized to collect readings from the

torque transducer and transfer the readings to a personal computer for further processing.

Adjustments were made to the rheometer to reduce errors in the measurement. The

adjustment prevents sample from entering the gap between lower plate and the side wall,

which otherwise will produce extra torque and make the estimation of shear stress more

difficult. The adjustment is shown in Figure 16. The radius of rheometer after the

adjustment is about 110 mm. 

3.5.2. Test procedures

The test procedures are described as follows:

1. Before adding the oil into the rheometer, the rheometer ran empty to record the

torque induced by rheometer itself. The PMac data acquisition device was set-up to

work at 50 Hz, which means 50 readings were taken per second. At 2.09 rad/s,

3.14 rad/s, 4.18 rad/s, 5.23 rad/s and 6.28 rad/s (20, 30, 40, 50, and 60 rpm), the

torque was measured for 10 s. The average of the readings at a certain rotational

speed was used as the frictional torque T ́ at that speed.

2. The oil was poured into the rheometer to the level of the upper vane. The rheometer

ran at 2.09 rad/s (20 rpm) for 1 min before measurements were taken. Torque was

then measured for 10 s each at 2.09 rad/s, 3.14 rad/s, 4.18 rad/s, 5.23 rad/s and 6.28

rad/s (20, 30, 40, 50, and 60 rpm). Then torque was measured for 10 s each at 6.28

rad/s, 5.23 rad/s, 4.18 rad/s, 3.14 rad/s and 2.09 rad/s (60, 50, 40, 30, and 20 rpm).

The average of the readings (acceleration and deceleration processes) at each

rotational speed was used as the torque (T0) at that speed.

3. The torque, T, at certain speed was calculated as T = T0 – T ́

4. The equations to convert torque and rotational speed to shear stress and shear rate

are [12, 13]:
26

60

2πN Ω =

h

RΩ

γ =

(3 ) 2

1

3 Ω = + Ω

d

dT T

πR

τ

[ 4]

where

Ω = Angularity speed (rad/s),

N= rotational speed (rpm),

ř = strain rate (1/s),

R = radius of rheometer (0.12 m),

h= distance between two plates (0.11 m),

τ = shear stress (Pa),

T = torque (N·m),

dT/dΩ = Bingham model slope of Ω-T curve.

The reproducibility of rheological measurements was checked previously using marble

concrete, i.e., concrete with coarse aggregate being glass spheres. The results are shown

in Figure 17. It is found that the deviation of the data is acceptable and the reproducibility

is good.

Figure 15. Parallel-plate concrete rheometer at UIUC.
27

A

B

Figure 16: Sketch of UIUC rheometer (A) and detailed dimensions of the rheometer

(B)
28

 Figure 17: Reproducibility of rheological measurements using the UIUC rheometer

0

1000

2000

3000

4000

5000

6000

7000

8000

0 5 10 15 Shear rate(1/s)

Shear stress (Pa)

Test 1 Test 2 Test 3 Linear (Test 2) Linear (Test 1) Linear (Test 3)
29

4. Measurements Using Oil

4.1. Materials and Procedure

To begin assessing if a reference material could be developed, oil was measured in all

concrete rheometers as the last measurement on Day 3 and at a later date for the UIUC

rheometer. NIST also measured the oil using a parallel plate rheometer designed and

calibrated for fluids. Each concrete rheometer was filled with Dow Corning 200(R)

Fluid, 30,000 CST. This material is a high viscosity fluid polydimethylsiloxane. The

nominal viscosity according to the manufacturer is 29.1 Pa·s and the density is

970 kg/m3

. This corresponds to a kinematic viscosity of 0.03 Pa·s (30 000 cs). The

kinematic viscosity is the ratio between the viscosity and the density.

The only rheometer not described in section 3 is the NIST rheometer. It is a parallel plate

rheometer normally used for polymers or oils. It consists of two plates with a smooth

surface and a diameter of 35 mm. The rheometer is controlled by a computer that changes

rotation speed in decreasing or increasing steps and measures torque on the top plate. The

temperature of the material under test is also controlled by a circulating water bath. The

gap or distance between the plates can be adjusted. This rheometer is calibrated using

standard oils. Further details on this rheometer are given in Ref. [30].

4.2. Results and Discussion

Using the calibrated NIST rheometer, two measurements were done with the oil at a

temperature of 24.4 °C ± 0.4 °C. Each measurement was performed at two gaps of 1 mm

and 0.5 mm ± 0.001 mm. The viscosity obtained was 29.5 Pa·s ± 0.6 Pa·s. This value

was taken as the reference for analysis of the results from the concrete rheometers.

Table 5 shows the results obtained with the oil with the concrete rheometers. All the

details, data and curves are shown in Appendix A. It should be noted that the BTRHEOM

could not be used to measure the oil as shown by the associated negative viscosity. The

reason for this is given below. Correction coefficients were calculated by dividing the

viscosity by the reference viscosity for all rheometers except the BTRHEOM. These

factors are shown in Table 5. Results from two rheometers are within 30 % error of the

correct value (BML and Two-Point test). The IBB reports a value 3 times higher than the

correct value. This is not surprising as the IBB is not calibrated against an oil and does

not report viscosity in fundamental units.

It is worth examining why the BTRHEOM was not able to measure the oil. It should be

said that the BTRHEOM is not designed to measure Newtonian liquids as shown by the

negative values measured (Table 5). The following section regarding the

inappropriateness of testing oil in the BTRHEOM is a direct excerpt from personal email

correspondence [31]:

Testing oil with the BTRHEOM is of little relevance, because the rheometer is

designed to characterize granular fluids of soft to fluid consistency (i.e. slump

value higher than 100 mm). A torsional motion is imposed to the hollow,
30

cylindrical material specimen, by using two systems of blades (one at the bottom,

one at the top of the specimen). The lower blades avoid rotation of the lower

section of the specimen, while the upper blades force concrete to rotate around

the vertical axis. Between these two sections, concrete can only have a torsional

motion - i.e. a local particle rate that is a linear function of both radius and

height - provided that the vertical walls do not perturb this theoretical rate field.

In reality, a friction takes place in the vicinity of vertical walls, but, thanks to the

spontaneous formation of a limit layer (made up with water and fine elements),

this friction is low (much lower than the concrete yield stress). This assumption

has been demonstrated both by experiments and numerical simulations [25].

Replacing concrete by oil, the level of friction will be the same, whatever the

bounds of the specimen (horizontal or vertical). In addition, the blades will create

local turbulent motion in the oil. The result will be a rate field quite different from

the torsional one, which is accounted for in the calculation of Bingham constants.

As a conclusion, it is not the nature of rheological behavior which matters

(Newton or Bingham), but the granular nature of the material. The BTRHEOM is

suitable for concrete, less suitable for mortar, unsuitable for grout and any other

fine material, including water, oil, etc...

The results obtained from the UIUC rheometers are shown in Appendix A. The frictional

torque T was about 1 N·m. The calculated yield stress was 102 Pa and plastic viscosity

was 283 Pa·s. It can be seen that the viscosity value is about ten times higher than the

expected value. To test the reproducibility of rheological measurements, testing was

repeated twice. It was found that the there was no significant difference from the previous

results. One possible reason for this discrepancy could be similar to the one described for

the BTRHEOM as both rheometers have a similar geometry.
31

Table 5: Results with oil using the various rheometers

BML BTRHEOM* IBB IBB portable Two-point Test 

Yield

Stress

Plastic

Viscosity

Yield

Stress

Plastic

Viscosity

Yield

Stress

Plastic

Viscosity

Yield

Stress

Plastic

Viscosity

Yield

Stress

Plastic

Viscosity

Mixture

Reference

τo

(Pa)

μ

(Pa·s)

τo

(Pa)

μ

(Pa·s)

τo

(N·m)

μ

(N·m·s)

τo

(N·m)

μ

(N·m·s)

τo

(Pa)

μ

(Pa·s)

O1 9 24 357 32 0.0

(-0.333)

10.02 0.0

(-0.182)

11.04 0♠ 49 

O2 9 24 444 -8 0.0

(-0.328)

10.03 0.0

(-0.170)

11.03 0♠ 44 

O3 - - 221 -23 - -- - - 0♠ 39 Averagevalue

24.0 ±0.0

N/A 10.0 ±

0.01

11.0 ± 0.01 44 ± 4 

Correctionfactor

1.23 2.94 2.67 0.67 

♠ negative recorded values for yield stress, which can be considered as zero

* The BTHREOM is not designed to measure oil as discussed in the text.
32

5. Results for Concrete and Mortar Mixtures

Table 6 shows the results obtained by the rheometers on the concrete and mortar

mixtures, in test order within each group. (Details of the mixtures and the single point test

results – slump etc. – have been given in Table 2 to Table 4). The results from the BML,

BTRHEOM and the two-point workability test are in fundamental units (Pa and Pa·s for

yield stress, τ0 and plastic viscosity, μ, respectively). However, the results of IBB and

IBB portable are in N·m and N·m·s for the yield (G) and plastic viscosity (H) terms,

respectively.

The range of rheological properties obtained for the concrete mixtures by each instrument

is shown in Figure 18. As intended, a wide range of combinations was obtained. The

BML and BTRHEOM show a largely similar pattern, with the two-point and IBB both

showing a pattern lacking a high yield stress/high plastic viscosity region, largely due to

high plastic viscosities recorded by both instruments for some of the low yield stress

mixtures.

For comparison, the ranges obtained in the tests at LCPC are shown in Figure 19. It can

be seen that these included mixtures with higher yield stresses. The MB tests have a

greater number of mixtures with low yield stresses, as in the experimental plan.
33

Table 6: Results obtained with all mixtures. The mixture # is given to simplify the plot of some data in graphs.

Yield

Stress

Plastic

Viscosity

Yield

Stress

Plastic

Viscosity

Yield

Stress

Plastic

Viscosity

Yield

Stress

Plastic

Viscosity

Yield

Stress

τo

(Pa)

μ

(Pa·s)

τo

(Pa)

μ

(Pa·s)

g

(N·m)

h

(N·m·s)

g

(N·m)

h

(N·m·s)

τo

(Pa)

Mix

BML BTRHEOM IBB IBB portable 

Concrete

1 D1M1Conc - - 6.94 7.86 7.16 10.01 2 D1M2Conc - - 1236 110 3.84 7.97 5.34 8.69 3 D1M3Conc 273 24 1005 103 2.09 5.90 3.22 7.44 4 D1M4Conc 300 36 864 114 2.73 7.60 3.90 9.11 5 D1M5Conc 528 28 1084 69 4.92 6.83 5.98 7.73 6 D2M1Conc 584 32 1120 127 5.63 9.37 7.50 9.22 7 D2M2Conc 39 22 324 100 0.34 9.05 1.25 11.29 8 D2M3Conc 3 57 161 143 0.0 (-1.97) 47.42 0.0 (-1.57) 37.67 9 D2M4Conc 30 38 491 102 0.75 17.50 0.73 25.38 10 D2M5Conc 55 58 88 164 0.73 26.52 0.69 30.35 11 D2M7Conc 38 55 158 138 0.33 26.24 0.48 26.86 12 D3M1Conc 416 46 628 167 4.18 10.52 4.40 14.29 13 D3M2Conc 35 17 283 52 0.66 8.04 0.78 9.42 14 D3M3Conc 303 36 925 134 2.64 10.23 3.50 12.28 15 D3M4Conc 290 23 670 105 1.39 6.27 2.72 6.86 16 D3M5Conc 55 42 233 91 0.53 18.16 1.00 18.82 17 D3M6Conc 235 39 687 71 3.27 13.50 3.36 16.09 

Mortar

18 D1M1Mort - - 742 (131)* 100 (149)* 1.13 2.09 1.60 1.91 19 D1M2Mort - - 634 2 1.12 2.14 1.46 2.07 20 D2M1Mort 224 2 550 1 1.19 1.95 1.65 1.93 21 D2M5Mort 254 16 345 66 2.07 5.78 2.27 6.23 22 D2M6Mort 16 6 177 50 - - 0.0 (-0.15) 3.91 
34

♥ the recorded plastic viscosity values were low or negative for these mixtures. The yield stress values were high (and slumps relatively low

testing the air pockets created immediately behind the impeller blades may not have refilled with concrete or mortar before the next pass of 

low values of torque at increasing impeller speed, and hence invalid plastic viscosity. There is sufficient confidence in the yield stress value

subsequent analysis.

♠ negative recorded values for yield stress, which can be considered as zero

* Values in parenthesis are from a second test for the BTHREOM
35

Figure 18: Range of Bingham properties measured in tests at MB

Figure 19: Range of Bingham properties measured in tests at LCPC

(b) results at MBT: BTRheom

0

200

400

600

800

1000

1200

1400

0 50 100 150 200

plastic viscosity (Pa.s)

yield stress (Pa)

high yield mixes

low yield mixes

(a) results at MBT: BML 

0

100

200

300

400

500

600

700

0 20 40 60 80

plastic viscosity (Pa.s)

yield stress (Pa)

high yield mixes

low yield mixes

(c) results at MBT: Two-point

0

200

400

600

800

1000

0 50 100 150 200

plastic viscosity (Pa.s)

yield stress (Pa)

high yield mixes

low yield mixes

(d) results at MBT: IBB

0

1

2

3

4

5

6

7

8

0 10 20 30 40 50

viscosity term (Nms)

yield term (Nm)

high yield mixes

low yield mixes

(b) results at LCPC: BT RHEOM

0

500

1000

1500

2000

2500

0 50 100 150 200

plastic viscosity (Pa.s)

yield stress (Pa)

(a) results at LCPC: BML

0

200

400

600

800

1000

0 20 40 60 80 100 120

plastic viscosity (Pa.s)

yield stress (Pa)

(c) results at LCPC: Two-point

0

200

400

600

800

1000

1200

0 20 40 60 80 100

plastic viscosity (Pa.s)

yield stress (Pa)

(d) results at LCPC: IBB

0

2

4

6

8

10

12

0 5 10 15 20

viscosity term (Nms)

yield term (Nm)
36

6. Discussion of Results with Concrete and Mortar

6.1. Correlation Between Single Point Tests and Rheometer Results for Concrete

For the tests on concrete, the correlation coefficients R for the relationships between the yield stress

values and the slump, slump flow, T50 and V-funnel measurements are shown in the last three

columns of Table 7, and those for the corresponding relationships with plastic viscosity in the last

three columns of Table 8. The significance of the correlation can be assessed using Table 9, which

gives, for two levels of confidence, the maximum values of absolute value of R that could be

obtained by chance alone when no correlation exist. Where available, the coefficients for the

previous tests at LCPC are also given in Table 7 and Table 8. Table 7 shows that good correlations

with absolute values of coefficients greater than 0.8 (except for one value) were obtained between

the yield stresses for each instrument and both slump (as in the LCPC tests) and slump flow values.

The relationships are shown in Figure 20 and Figure 21. Poor correlations were obtained between

the yield stresses and the T50 and V-funnel values, which is to be expected, as these are

measurements of flow rate.

The correlations between the plastic viscosity values and slump and slump flow values are poor, but

with the T50 and V-funnel values are good (Table 8), again as expected. These are shown in Figure

22 and Figure 23 respectively, with Figure 22 showing that in most cases the correlation would be

improved if one or two outlying data points were ignored.

Figure 20: Relationships between yield stress/yield term and slump for concrete mixtures

0

200

400

600

800

1000

1200

1400

100 125 150 175 200 225 250

slump (mm)

yield stress (Pa)

BML

BTRHEOM

Two-point

0

1

2

3

4

5

6

7

8

100 125 150 175 200 225 250

slump (mm)

yield value (Nm)

IBB

IBB portable
37

 Figure 21: Relationships between yield stress/yield term and slump flow for concrete mixtures

Figure 22: Relationships between plastic viscosity/viscosity term and V-funnel flow time for

concrete mixtures

Figure 23: Relationships between plastic viscosity/viscosity term and T50 times for concrete

mixtures

Yield stress vs slump flow 

0

200

400

600

800

1000

300 350 400 450 500 550 600 650 700

slump flow (mm)

yield stress (Pa)

BML

BTRHEOM

Two-point

0

1

2

3

4

5

300 350 400 450 500 550 600 650 700

slump flow (mm)

yield value (Nm)

IBB

IBB portable

0

20

40

60

80

100

120

140

160

180

0 2 4 6 8 10

V-funnel flow time (secs)

plastic viscosity (Pas)

BML

BTRHEOM

Two-point

0

10

20

30

40

50

0 2 4 6 8 10

V-funnel flow time (secs)

viscosity term (Nms)

IBB

IBB portable

Plastic viscosity vs T50

0

20

40

60

80

100

120

140

160

180

012345

T50 (secs)

plastic viscosity (Pa.s)

BML

BTRHEOM

Two-point

Viscosity term vs T50

0

10

20

30

40

50

012345

T50 (secs)

viscosity term (Nms)

IBB

IBB portable
38

6.2. Comparison Between Rheometers

6.2.1. General Trends

Figure 24 and Figure 25 have been plotted from the data in Table 6 and show the yield stress and

plastic viscosity values respectively plotted against mixture number. To simplify the graphs, the

results from the IBB portable, which are very similar to those from the IBB, have not been plotted in

either graph.

As with the tests at LCPC [3], all the rheometers show similar trends for both constants, which is

again very encouraging. Also as at LCPC, the yield stresses appear to be the more consistent, i.e.,

the trends are the same for all rheometers. 

Figure 24: Plastic viscosity vs. concrete or mortar mixtures. The lines connecting the points are

only used to guide the eye and are not meant as implication of a relationship between the points.

Figure 25: Yield stress vs. concrete or mortar mixtures. The lines connecting the points are only

used to guide the eye and are not meant as implication of a relationship between the points.

0

20

40

60

80

100

120

140

160

180

0 5 10 15 20 25

Test number

Plastic Viscosity [Pas]

0

5

10

15

20

25

30

35

40

45

50

Plastic Viscosity [Nms]

BML

BTRHEOM

Two-Point

IBB

Concrete Mortar 

0

200

400

600

800

1000

1200

1400

0 5 10 15 20 25

Test number

Yield Stress [Pa]

0

1

2

3

4

5

6

7

8

9

10

Yield Stress [Nm]

BML

BTRHEOM

Two-Point

IBB

Concrete Mortar 
39

6.2.2. Comparison of measurements on concrete mixtures

The correlation coefficients, R, for results between pairs of rheometers are given in columns 3 to 6 of

Table 7 and Table 8 for yield stress and plastic viscosity respectively, together with the

corresponding values from the LCPC tests where these exist. Yield stress coefficients (Table 7) are

all higher than 0.84, indicating good correlation (Table 9). The highest values were obtained

between BML vs. IBB portable (0.98) and IBB vs. IBB portable (0.97). Plastic viscosity coefficients

(Table 8) are generally lower. The absolute values of the coefficients for those relationships between

the BTRHEOM and the two-point, IBB and IBB portable are all less than 0.5, indicating poor

correlation.

The regression coefficients for the relationships are given in Table 10 and Table 11 for yield stress

and plastic viscosity respectively, and the data and regression lines are plotted in figures 25(1) and

(2), and 26(1) and (2).

None of the slope coefficients for either the yield stress or plastic viscosity relationships between the

three instruments that give values in fundamental units are close to the ideal value of 1. However,

the values of slopes for the IBB and IBB portable correlations are, as would be expected, closer to 1

(1.12, 0.844, 1.11, 0.815 from Table 10 and Table 11). The fact that they are not equal to 1 may be

attributable to the nature of the rougher surface of the impeller used for IBB portable compared to

that of the IBB.

The data and regression line plots for yield stress values (Figure 26 and Figure 27) all have a cluster

of points at low yield stress, as intended in the experimental plan. The generally poorer correlations

between the sets of plastic viscosities are apparent in Figure 28 and Figure 29, but, as before, in some

cases much improved correlations would be obtained if one or two outlying points were ignored.

Table 7: Correlation coefficients R for yield stress values of concrete mixtures

BML BTRHEOM Two-point IBB IBB

portable slump slump

flow T50 V-funnel

time

BML 0.89 (0.97) 0.96 (0.94) 0.96 (0.81) 0.98 -0.90 (-0.96) -0.95 -0.27 0.00

BTRHEOM 0.86 (0.97) 0.84 (0.82) 0.90 -0.82 (-0.95) -0.80 -0.66 -0.11

Two-point 0.91 (0.90) 0.96 -0.91 (-0.96) -0.92 0.48 -0.03

IBB 0.97 -0.65 (0.86) -0.85 -0.35 0.14

IBB portable -0.84 (-0.94) -0.91 -0.69 -0.03

 ( ) : coefficients R from tests at LCPC

Table 8: Correlation coefficients R for plastic viscosity of concrete mixtures

BML BTRHEOM Two-point IBB IBB

portable slump slumpflow T50 V-funneltime

BML 0.71 (0.84) 0.70 (0.45) 0.83 (0.96) 0.86 0.38 0.07 0.85 0.86

BTRHEOM 0.30 (0.79) 0.45 (0.86) 0.45 0.15 -0.23 0.90 0.58

Two-point 0.90 (0.52) 0.95 0.58 0.52 0.89 0.57

IBB 0.94 0.39 0.35 0.83 0.70

IBB portable 0.54 0.48 0.89 0.67

( ) : coefficients R from tests at LCPC
40

Table 9: Critical values for the absolute value of the correlation coefficient R of a sample

extracted from a normal distribution. Α is the confidence, and γ = n -2, where n is the number of

points.

α 95 % confidence 99 % confidence

2 variables 2 variables

γ |R| |R|

14 0.497 0.623

15 0.482 0.606

16 0.468 0.590

17 0.456 0.575
41

Table 10: Coefficients of regression A and B for yield stress of concrete mixtures (Y = A X + B)

BML BTRHEOM Two-point IBB IBB port

(Pa) (Pa) (Pa) (N·m) (N·m) 

A B A BAB A B A 

BML (Pa) 1.66 229.9 1.34 76.6 0.0090 0.062 0.0113 BTRHEOM (Pa) 0.48 -64.0 0.61 1.17 0.0040 -0.363 0.0053 -

Two-point (Pa) 0.688 -36.16 1.225 156.8 0.0067 -0.342 0.0081 -

IBB (N·m) 102.4 9.51 178.2 249.2 123.6 114 1.12 

IBB portable(N·m) 85.5 -11.7 154.4 191.9 113.5 61.84 0.844 -0.196 

Slump (mm) -3.58 1050 -6.14 2018 -4.75 1468 -0.032 9.52 -0.04 

Notes: in Table 10 and Table 11:

Y = A X + B, where Y = column titles, X = row titles

Table 11: Coefficients of regression A and B for plastic viscosity of concrete mixtures (Y = A X + B)

BML BTRHEOM Two-point IBB IB

(Pa·s) (Pa·s) (Pa·s) (N·m·s) 

AB A BAB A B A 

BML (Pa·s) 1.84 44.3 2.15 -12.4 0.698 -10.85 0.6BTRHEOM(Pa·s) 0.272 6.39 0.387 21.9 0.151 -2.47 0.1

Two-point(Pa·s) 0.227 22.3 0.233 98.47 0.246 -0.52 0.2

IBB (N·m·s) 0.927 23.1 1.32 92.76 3.52 10.3 0.8

IBB portable(N·m·s) 1.17 17.6 1.65 85.9 4.26 -6.65 1.11 -3.03

Notes: in Table 10 and Table 11:

Y = A X + B, where Y = column titles, X = row titles
42

Figure 26: Yield stress correlations

(a) yield stress - BTRHEOM vs BML

0

200

400

600

800

1000

1200

1400

0 100 200 300 400 500 600 700

yield stress (Pa) - BML

yield stress (Pa) - BTRHEOM 

(b) yield stress - Two-point vs BML

0

200

400

600

800

1000

0 100 200 300 400 500 600 700

yield stress (Pa) - BML

yield stress (Pa) - Two point 

(c) yield stress - IBB vs BML

0

2

4

6

8

0 100 200 300 400 500 600 700

yield stress (Pa) - BML

yield stress (Pa) - IBB 

(d) yield stress - IBB portable vs BML

0

2

4

6

8

0 100 200 300 400 500 600 700

yield stress (Pa) - BML

yield stress (Pa) - IBB portable

(e) yield stress - Two-point vs BTRHEOM

0

100

200

300

400

500

600

700

800

900

1000

0 200 400 600 800 1000 1200 1400

yield stress (Pa) - BTRHEOM

yield stress (Pa) - Two-point 

(f) yield stress - IBB vs BTRHEOM

0

1

2

3

4

5

6

0 200 400 600 800 1000 1200 1400

yield stress (Pa) - BTRHEOM

yield stress (Pa) - IBB 
43

Figure 27: Yield stress correlations (cont)

(g) yield stress - IBB portable vs BTRHEOM

0

1

2

3

4

5

6

7

8

0 500 1000 1500

yield stress (Pa) - BTRHEOM

yield stress (Pa) - IBB portable

(h) yield stress - IBB vs Two-point

0

1

2

3

4

5

6

7

8

0 200 400 600 800 1000

yield stress (Pa) - Two-point

yield stress (Pa) - IBB 

(i) yield stress - IBB portable vs Two-point

0

1

2

3

4

5

6

7

8

0 200 400 600 800 1000

yield stress (Pa) - Two-point

yield stress (Pa) - IBB portable

(j) yield stress - IBB portable vs IBB

0

1

2

3

4

5

6

7

8

9

02468

yield stress (Pa) - IBB

yield stress (Pa) - IBB portable
44

Figure 28: Plastic viscosity correlations

(a) plastic viscosity - BTRHEOM vs BML

0

20

40

60

80

100

120

140

160

180

0 20 40 60 80

plastic viscosity (Pas) BML

plastic viscosity (Pas) BTRHEOM

(b) plastic viscosity - Tw o-point vs BML

0

20

40

60

80

100

120

140

160

180

0 20 40 60 80

plastic viscosity (Pas) BML

plastic viscosity (Pas) Two-point

(c) plastic viscosity - IBB vs BML

0

5

10

15

20

25

30

35

40

45

50

0 20 40 60 80

plastic viscosity (Pas) BML

plastic viscosity (Pas) IBB

(d) plastic viscosity - IBB portable vs BML

0

5

10

15

20

25

30

35

40

0 20 40 60 80

plastic viscosity (Pas) BML

plastic viscosity (Pas) IBB portable

(e) plastic viscosity - Two-point vs BTRHEOM 

0

20

40

60

80

100

120

140

160

180

0 50 100 150 200

plastic viscosity (Pas) BTHEOM

plastic viscosity (Pas) Two-point

(f) plastic viscosity - IBB vs BTRHEOM 

0

5

10

15

20

25

30

35

40

45

50

0 50 100 150 200

plastic viscosity (Pas) BTHEOM

plastic viscosity (Pas) IBB
45

Figure 29: Plastic viscosity correlations (cont)

(g) plastic viscosity - IBB portable vs BTRHEOM 

0

5

10

15

20

25

30

35

40

0 50 100 150 200

plastic viscosity (Pas) BTHEOM

plastic viscosity (Pas) IBB portable

(h) plastic viscosity - IBB vs Two-point

0

5

10

15

20

25

30

35

40

45

50

0 50 100 150 200

plastic viscosity (Pas) two-point

plastic viscosity (Pas) IBB

(i) plastic viscosity - IBB portable vs Two-point

0

5

10

15

20

25

30

35

40

0 50 100 150 200

plastic viscosity (Pas) two-point

plastic viscosity (Pas) IBB portable

(j) plastic viscosity - IBB portable vs IBB

0

5

10

15

20

25

30

35

40

45

0 10 20 30 40 50

plastic viscosity (Pas) IBB

plastic viscosity (Pas) IBB portable
46

6.2.3. Ranking of the concrete mixtures by the various rheometers

The graphs of yield stress and plastic viscosity versus mixture number (

Figure 24 and Figure 25) show there is some similarity between the results of the

different rheometers. The next step, as it was in Phase I, is to compare the classification

of the concrete mixtures by apparatus.

This type of comparison can be quantified by Kendall’s coefficient of concordance, W,

[32] (see Appendix E of ref. [3]). First, the ranking was established for each concrete by

each rheometer, both for yield stress (Table 12) and plastic viscosity (Table 13). This

comparison is made only on the rank given by each apparatus, which enables one to

include the IBB (for both “equivalent” yield stress and plastic viscosity). Nevertheless,

the same number of data points should be available for each rheometer. This precludes

mixtures # 5 and 6 from plastic viscosity measurements and mixtures #1 and 2 from both

measurements.

From the tables, it is clear that there is some correlation between the various devices for

both yield stress and plastic viscosity. For instance, Mixtures #5 and, #6, show similar

rankings for yield stress (Table 12). Mixtures #8, #10 and #11 show similar ranking for

the plastic viscosity (Table 13).

Table 12: Ranking of the yield stress of the concrete mixtures as determined by the

rheometers. The mixtures are ranked in increasing order of yield stress from 1 to 15.

Ranking Concrete Mixtures

according to 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

BML 9 11 14 15 5 1 2 6 4 13 3 12 10 7 8

BTRHEOM 13 11 14 15 6 3 7 1 2 8 5 12 9 4 10

IBB 9 11 14 15 3 1 7 6 2 13 5 10 8 4 12

IBB Portable 9 12 14 15 7 1 4 3 2 13 5 11 8 6 10

Two-Point 13 12 14 15 6 3 1 7 5 11 2 9 10 4 8

 Table 13: Ranking of plastic viscosity of the concrete mixtures as determined by the

rheometers. The mixtures are ranked in increasing order of yield stress from 1 to 13.

Ranking Concrete Mixtures

according to 3 4 7 8 9 10 11 12 13 14 15 16 17

BML 4 6 2 12 7 13 11 10 1 5 3 9 8

BTRHEOM 6 8 4 11 5 12 10 13 1 9 7 3 2

IBB 1 3 5 13 9 12 11 7 4 6 2 10 8

IBB Portable 2 3 5 13 10 12 11 7 4 6 1 9 8

Two-Point 3 1 6 13 10 12 11 2 5 7 4 8 9

Calculations of the Kendall’s coefficient of concordance, W (Appendix E of ref. [3]),

show it to be equal to 0.89 for yield stress and 0.72 for plastic viscosity. To test the

significance of the observed value of W, the distribution of W is considered in the
47

customary way to reject or accept the hypothesis that the classifications are independent.

That is, the classifications are not independent (at the 95 % confidence level) if the value

of W is greater than a reference value. Since the number of samples is greater than 7, the

following approximation is used to obtain the reference value [see ref 32 p. 98]. In the

equation r b(a 1)W 2 χ = − , 2 χ r is distributed in the form known in statistics as 2 χ with

ν = a −1 degrees of freedom, where a is the number of samples (15 for yield stress and

13 for plastic viscosity) and b is the number of devices (5 in this case). For yield stress,

( 1) 5 ( ) 15 1 .89 62.3 2 χ r = b a − W = × − × = , which is greater than 23.7 2 χν =15−1=14,.05 = . For

viscosity, 4 43. 2 χ r = , which is greater than 21.0 2 χ 12,.05 = . The tests show that the

classifications by the various devices are not independent. This implies that the

rheometers can be used to statistically rank the mixtures in the same order. From looking

at Table 12 and Table 13, it can be seen that quite a few rheometer rank some mixtures at

the same level. For instance, mixture 5 and 6 for yield stress are in position 14 and 15

respectively for all rheometers. Quite a few of the other mixtures have the same position

attributed by at least 3 rheometers.

6.2.4. Comparison of Results from Phase I (2000) and Phase II (2003) [3]

Only the concrete mixtures from Phase II are compared with the Phase I data. Comparing

the correlation coefficients for yield stress measurements obtained in the two series

(Table 7) shows that they were very similar. The coefficients for the plastic viscosity

(Table 8) are again generally lower than for yield stress, but have a wider range (as low

as 0.3 for BTRHEOM vs. Two-point). Table 14 and Table 15 give the correlation

coefficients calculated using all data from both phases. Regression coefficients for the

yield stresses and plastic viscosities for all concrete mixtures prepared in both phases are

given in Table 16 and Table 17, respectively.

Figure 30 and Figure 31 give a comparison between the data and regression lines

obtained for the four rheometers used both in the current tests and in the tests at LCPC,

again for yield stress and plastic viscosity respectively. Figure 30 shows broadly similar

correlations in each case, with near coincident regression lines in three cases. All those

involving the two-point test show a shift, which could indicate some change in the

calibration of the two-point test. However, this was checked immediately after the

apparatus returned from America, and no differences were obtained. Figure 31 shows the

much greater variety of behavior for plastic viscosity.

Table 14: Correlation coefficients, R, for yield stress values (MB and LCPC) for the

concrete mixtures.

BML BTRHEOM Two-point IBB Slump

BML 0.95 0.91 0.88 - 0.95

BTRHEOM. 0.86 0.85 - 0.93

Two-point 0.88 - 0.90

IBB - 0.86

Slump
48

Table 15: Correlation coefficients, R, for plastic viscosity (MB and LCPC) for the

concrete mixtures.

BML BTRHREOM Two-point IBB

BML 0.51 0.29 0.39

BTRHEOM 0.56 0.49

Two-point 0.90

IBB

Table 16: Regression coefficients A and B for yield stress (MB and LCPC) for the

concrete mixtures.

BML BTRHEOM Two-point IBB Slump

(Pa) (Pa) (Pa) (N·m) (mm)

A B A BAB A B A B

BML (Pa) 1.89 226.8 0.988 91.37 0.009 0.186 -0.219 274.2

BTRHEOM (Pa) 0.477 -77.37 0.475 14.51 0.004 -0.536 -0.110 294.2

Two-point (Pa) 0.831 -19.82 1.57 189.5 0.008 -0.252 -0.187 280.6

IBB (N·m) 90.81 54.54 176.3 325.1 99.6 124.7 -20.48 262.8

Slump (mm) -0.22 274 -7.9 2434 -4.3 1290 -0.032 9.37

Table 17: Regression coefficients A and B for plastic viscosity (MB and LCPC) for the

concrete mixtures.

BML BTRHEOM Two-point IBB

(Pa·s) (Pa·s) (Pa·s) (N·m·s)

AB A BAB A B

BML 0.930 52.23 0.439 33.12 0.139 6.64

BTRHEOM 0.282 17.33 0.461 7.55 0.095 3.61

Two-point 0.197 33.11 0.676 59.94 0.213 2.09

IBB 1.12 29.3 2.513 61.79 3.76 1.96

Notes: Y = A X + B, where Y = column titles, X = row titles
49

Figure 30: Yield tress correlations obtained at LCPC and MB for concrete mixtures

(a) BML/BTRHEOM

0

500

1000

1500

2000

2500

0 200 400 600 800 1000

yield stress (Pa) - BML

yield stress (Pa) - BTRHEOM

tests at MBT

tests at LCPC

(b) BML/Two-point

0

200

400

600

800

1000

1200

0 200 400 600 800 1000

yield stress (Pa) - BML

yield stress (Pa) - Two point

tests at MBT

tests at LCPC

(c) BML/IBB

0

2

4

6

8

10

12

0 200 400 600 800 1000

yield stress (Pa) - BML

yield stress (Nm) - IBB

tests at MBT

tests at LCPC

(d) BTRHEOM/Two-point

0

200

400

600

800

1000

1200

0 500 1000 1500 2000 2500

yield stress (Pa) - BTRHEOM

yield stress (Pa) - Two-point

tests at MBT

tests at LCPC

(e) BTRHEOM/IBB

0

2

4

6

8

10

12

0 500 1000 1500 2000 2500

yield stress (Pa) - BTRHEOM

yield stress (Nm) - IBB

tests at MBT

tests at LCPC

(f) Two-point/IBB

0

2

4

6

8

10

12

0 500 1000 1500

yield stress (Pa) - Two-point

yield stress (Nm) - IBB

tests at MBT

tests at LCPC

(a) BML/BTRHEOM

0

500

1000

1500

2000

2500

0 200 400 600 800 1000

yield stress (Pa) - BML

yield stress (Pa) - BTRHEOM

tests at MBT

tests at LCPC

(b) BML/Two-point

0

200

400

600

800

1000

1200

0 200 400 600 800 1000

yield stress (Pa) - BML

yield stress (Pa) - Two point

tests at MBT

tests at LCPC

(c) BML/IBB

0

2

4

6

8

10

12

0 200 400 600 800 1000

yield stress (Pa) - BML

yield stress (Nm) - IBB

tests at MBT

tests at LCPC

(d) BTRHEOM/Two-point

0

200

400

600

800

1000

1200

0 500 1000 1500 2000 2500

yield stress (Pa) - BTRHEOM

yield stress (Pa) - Two-point

tests at MBT

tests at LCPC

(e) BTRHEOM/IBB

0

2

4

6

8

10

12

0 500 1000 1500 2000 2500

yield stress (Pa) - BTRHEOM

yield stress (Nm) - IBB

tests at MBT

tests at LCPC

(f) Two-point/IBB

0

2

4

6

8

10

12

0 500 1000 1500

yield stress (Pa) - Two-point

yield stress (Nm) - IBB

tests at MBT

tests at LCPC

(a) BML/BTRHEOM

0

500

1000

1500

2000

2500

0 200 400 600 800 1000

yield stress (Pa) - BML

yield stress (Pa) - BTRHEOM

tests at MBT

tests at LCPC

(b) BML/Two-point

0

200

400

600

800

1000

1200

0 200 400 600 800 1000

yield stress (Pa) - BML

yield stress (Pa) - Two point

tests at MBT

tests at LCPC

(c) BML/IBB

0

2

4

6

8

10

12

0 200 400 600 800 1000

yield stress (Pa) - BML

yield stress (Nm) - IBB

tests at MBT

(a) BML/BTRHEOM

0

500

1000

1500

2000

2500

0 200 400 600 800 1000

yield stress (Pa) - BML

yield stress (Pa) - BTRHEOM

tests at MBT

tests at LCPC

(b) BML/Two-point

0

200

400

600

800

1000

1200

0 200 400 600 800 1000

yield stress (Pa) - BML

yield stress (Pa) - Two point

tests at MBT

tests at LCPC

(c) BML/IBB

0

2

4

6

8

10

12

0 200 400 600 800 1000

yield stress (Pa) - BML

yield stress (Nm) - IBB

tests at MBT

tests at LCPC

(d) BTRHEOM/Two-point

0

200

400

600

800

1000

1200

0 500 1000 1500 2000 2500

yield stress (Pa) - BTRHEOM

yield stress (Pa) - Two-point

tests at MBT

tests at LCPC

(e) BTRHEOM/IBB

0

2

4

6

8

10

12

0 500 1000 1500 2000 2500

yield stress (Pa) - BTRHEOM

yield stress (Nm) - IBB

tests at MBT

tests at LCPC

(f) Two-point/IBB

0

2

4

6

8

10

12

0 500 1000 1500

yield stress (Pa) - Two-point

tests at LCPC

(d) BTRHEOM/Two-point

0

200

400

600

800

1000

1200

0 500 1000 1500 2000 2500

yield stress (Pa) - BTRHEOM

yield stress (Pa) - Two-point

tests at MBT

tests at LCPC

(e) BTRHEOM/IBB

0

2

4

6

8

10

12

0 500 1000 1500 2000 2500

yield stress (Pa) - BTRHEOM

yield stress (Nm) - IBB

tests at MBT

tests at LCPC

(f) Two-point/IBB

0

2

4

6

8

10

12

0 500 1000 1500

yield stress (Pa) - Two-point

yield stress (Nm) - IBB

tests at MBT

tests at LCPC
50

Figure 31: Plastic viscosity correlations obtained at LCPC and MB for concrete

mixtures

(a) BML/BTRHEOM

0

20

40

60

80

100

120

140

160

180

200

0 20 40 60 80 100 120

plastic viscosity (Pas) BML

plastic viscosity (Pas) 

BTRHEOM

tests at MBT

tests at LCPC

(b) BML/Two-point

0

20

40

60

80

100

120

140

160

180

0 20 40 60 80 100 120

plastic viscosity (Pas) BML

plastic viscosity (Pas) 

Two-point

tests at MBT

tests at LCPC

(c) BML/IBB

0

5

10

15

20

25

30

35

40

45

50

0 20 40 60 80 100 120

plastic viscosity (Pas) BML

plastic viscosity (Nm.s) IBB

tests at MBT

tests at LCPC

(d) BTRHEOM/Two-point

0

20

40

60

80

100

120

140

160

180

0 50 100 150 200

plastic viscosity (Pas) BTRHEOM

plastic viscosity (Pas) Twopoint

tests at MBT

tests at LCPC

(e) BTRHEOM/IBB

0

5

10

15

20

25

30

35

40

45

50

0 50 100 150 200

plastic viscosity (Pas) BTRHEOM

plastic viscosity (Nm.s) IBB

tests at MBT

tests at LCPC

(f) Two-point/IBB

0

5

10

15

20

25

30

35

40

45

50

0 50 100 150 200

plastic viscosity (Pas) Two-point

plastic viscosity (Nm.s) IBB

tests at MBT

tests at LCPC

(a) BML/BTRHEOM

0

20

40

60

80

100

120

140

160

180

200

0 20 40 60 80 100 120

plastic viscosity (Pas) BML

plastic viscosity (Pas) 

BTRHEOM

tests at MBT

tests at LCPC

(b) BML/Two-point

0

20

40

60

80

100

120

140

160

180

0 20 40 60 80 100 120

plastic viscosity (Pas) BML

plastic viscosity (Pas) 

Two-point

tests at MBT

tests at LCPC

(c) BML/IBB

0

5

10

15

20

25

30

35

40

45

50

0 20 40 60 80 100 120

plastic viscosity (Pas) BML

plastic viscosity (Nm.s) IBB

tests at MBT

tests at LCPC

(d) BTRHEOM/Two-point

0

20

40

60

80

100

120

140

160

180

0 50 100 150 200

plastic viscosity (Pas) BTRHEOM

plastic viscosity (Pas) Twopoint

tests at MBT

tests at LCPC

(e) BTRHEOM/IBB

0

5

10

15

20

25

30

35

40

45

50

0 50 100 150 200

plastic viscosity (Pas) BTRHEOM

plastic viscosity (Nm.s) IBB

tests at MBT

tests at LCPC

(f) Two-point/IBB

0

5

10

15

20

25

30

35

40

45

50

0 50 100 150 200

plastic viscosity (Pas) Two-point

plastic viscosity (Nm.s) IBB

tests at MBT

tests at LCPC
51

6.3. Repeatability of Data

Three mixtures design were repeated three times to attempt to determine the repeatability

of the results. The mixtures were:

• HiYld concrete: D1M1Conc, D1M2Conc, D2M1Conc

• LoYld concrete: D2M3Conc, D2M5Conc, D3M5Conc

• HiYld mortar: D1M1mort, D1M2mort, D2M1mort

Table 18 and Table 19 show the average, standard deviation and coefficient of variation

in percentage for the yield stress and the plastic viscosity respectively determined from

the rheometers. Table 20 shows instead the average, standard deviation and coefficient

of variation of the other tests. The coefficient of variation (CV) is defined as the ratio of

the standard deviation to the average in percentage.

In general, it seems that the CV as calculated in Table 18 and Table 19 is very high. Most

of time the CV is higher than 10% and even as high as 166% in one case. This could be

attributed to the fact that the concrete mixtures might not be exactly identical in

composition. For instance, the water content, as shown in Table 2 - Table 4, does vary

slightly. And also, the value of ∆t varies for each mixture, in some cases widely. On the

other hand, the results in Table 20 show a lower CV for most tests and concrete mixtures

than the CV from Table 18 and Table 19. This could imply two interpretations: 1) the

rheometer measurements are more sensitive to small changes than the non-rheometer

tests; or 2) another factor, not identified here, corrupted the data. There are not enough

data to be able to discriminate between these hypothesis.

In summary, these repeatability data are disappointing and it is not clear how to proceed,

as the non-repeatability sheds a light of great uncertainty on all the data and correlation

factors calculated here and in Phase I. This lack of repeatability should be confirmed by

conducting many more tests, as three are not enough to adequately describe the statistical

nature of the associated variability. Unfortunately, this was not possible under the current

test program.
52

Table 18: Average yield stress for the mixture repeatability. No standard deviation was

calculated when only one value was available.

Mixture

type

BML

[Pa]

BTHREOM

[Pa]

IBB

[N·m]

IBB

portable

[N·m]

Twopoint

[Pa]

Average 584.0 1177.5 5.5 6.7 817.7

Standard

Deviation 81.3 1.6 1.2 137.8

HiYld

Conc

CV [%] 7 28 17 17

Average 46.7 270.7 0.7 0.8 135.0

Standard

Deviation 14.4 204.1 0.1 0.2 107.6

LoYld

Conc

CV [%] 31 75 18 21 80

Average 224.0 642.0 1.1 1.6 208.3

Standard

Deviation 96.2 0.0 0.1 31.5

HiYld

Mort

CV [%] 15 3 6 15

Table 19: Average plastic viscosity for the mixture repeatability. No standard deviation

was calculated when only one value was available.

Mixture

type

BML

[Pa·s]

BTHREOM

[Pa·s]

IBB

[N·m·s]

IBB

portable

[N·m·s]

Twopoint

[Pa·s]

Average 32.0 118.5 8.4 9.3 20.0

Standard

Deviation

12.0 0.8 0.7 8.5

HiYld

Conc

CV [%] 10 10 7 42

Average 46.0 119.0 20.7 24.9 95.0

Standard

Deviation

10.6 39.4 5.0 5.8 23.6

LoYld

Conc

CV [%] 23 33 24 23 25

Average 2.0 34.3 2.1 2.0 15.0

Standard

Deviation 56.9

0.1 0.1

HiYld

Mort

CV [%] 166 5 4
53

Table 20: Average for the non-rheometer tests

Mixture

type

Slump

(mm)

Slump

Flow

(mm)

U-boxRiseHt

(mm)

V-funnel

time

(s)

Average 133.3 201

Standard

Deviation

16.4 29.4

HiYld

Conc

CV [%] 12 14

Average 244.5 470.0 368.3 2.1

Standard

Deviation

4.9 18.4 22.7 0.2

LoYld

Conc

CV [%] 2 4 6 10

Average 588.3 351.3 6.1

Standard

Deviation

51.5 4.0 1.1

HiYld

Mort

CV [%] 9 1 18
54

6.4. Relative Viscosity: Mortar and Concrete

It is clear from the results shown here and from the analysis in previous sections that the

comparison of the absolute values of the rheometers can only be done through a fitted

correlation curve. This is due to the fact that the units and other geometrical factors are

widely different from rheometer to rheometer. Ferraris and Martys [33] have designed the

concept of relative viscosity that could be used to compare results from rheometers with

different geometries. They define the true or absolute plastic viscosity as the slope of the

curve, shear stress vs. shear rate, corrected by a function, f, which depends on the

rheometer geometry and experimental conditions. So the following equation could be

used:

f (M ,C) V

T

T = ⋅ ∆

∆

η [ 5]

 where ∆T / ∆V = slope of the torque (T) versus rotational speed (V) = H

ηT = true or absolute plastic viscosity

f(G, C) = function depending on the rheometer geometry (M) and experimental

conditions (C).

The function f is not fully known for most of the concrete rheometers due to their

complex geometry and the lack of a standard material that could be used for calibration.

Therefore, to eliminate the function f from the calculation, they defined the relative

viscosity the ratio, ηT1 ηT 2 , where the indices 1 and 2 stand for the two mixtures tested

in the same rheometer. The equation (10) than could be written as follows:

2

1

2

1

2

2

1

1

( , )

( , )

T

T

T

T

f G C

f G C

V

T

V

T

η

η

η

η = ⋅

⋅ =

∆

∆

∆

∆ [ 6]

For instance, material 1 could be the concrete while material 2 could be the mortar with

the same composition of the concrete without the coarse aggregates. In equation (6) the

relative viscosity does not depend on the rheometer used.

If this concept is applied to the results obtained here, a suitable reference mixture should

be identified. The definition of relative viscosity in the rheology is usually given as [34]

the ratio of the viscosity in a suspension (concrete as coarse aggregates in mortar) to the

viscosity of the suspending medium (mortar). Obviously, a pseudo relative viscosity

could be defined and another mixture could be used, but a mortar will be used as a

reference to demonstrate the method.

In examining Table 6, it can be seen that only one mortar, “D2M5Mort”, has data for all

rheometers. Ideally, the mortar and the concrete should be from the same matrix. Another
55

criterion for selection is to use the average of the one mortar that was repeated three

times. Unfortunately as shown in section 6.3, it is clear that the error attached to that

mortar and the missing data for some of the rheometers make it unusable. Therefore, the

only reasonable possibility to calculate the relative viscosities for all the concrete was to

use “D2M5Mort“ as a reference. It is clear that if this approach was to be used, better

data for the mortar would need to be obtained. Figure 32 shows the results obtained.

Figure 32: Relative viscosity (using D2M5Mort as a reference) for each rheometer as

a function of the mixture number

To determine the spread of the relative viscosities for any mixture, the average, standard

deviation and the coefficient of variation were calculated (Table 21). About 58 % of

relative viscosities have a CV less than 30 %. The mortar used as a reference was

arbitrarily selected as the only one for which all the rheometers reported a measurement.

It could be expected that with a better reference the CV could be lowered further.

Nevertheless, the comparison of the plastic viscosities using different rheometers is easier

to achieve from Figure 32 than from

Figure 24.

Due to flaws in the selection of the reference, this approach is given here as an

illustration of another way to compare results from various rheometers. It should be kept

in mind that otherwise the data from IBB and the other rheometers could not be plotted

on the same graph using one Y-axis.

0

1

2

3

4

5

6

7

8

9

0 5 10 15 20

Mix Number

Relative Viscosity

BML

BTHREOM

IBB

IBB portable

Two-point
56

Table 21: Average relative viscosity and coefficient of variation (using D2M5Mort as a

reference).

Mixture

#

Mixture Average Standard

Deviation

CV

[%]

1 D1M1Conc 1.2 0.5 43.6

2 D1M2Conc 1.4 0.2 15.7

3 D1M3Conc 1.3 0.2 16.8

4 D1M4Conc 1.5 0.6 40.7

5 D1M5Conc 1.3 0.3 23.6

6 D2M1Conc 1.8 0.2 14.0

7 D2M2Conc 1.7 0.4 22.2

8 D2M3Conc 5.4 2.5 46.1

9 D2M4Conc 3.1 1.1 37.4

10 D2M5Conc 4.1 1.1 26.1

11 D2M7Conc 3.8 1.1 28.1

12 D3M1Conc 2.1 0.7 30.9

13 D3M2Conc 1.4 0.5 34.1

14 D3M3Conc 2.1 0.2 11.1

15 D3M4Conc 1.4 0.3 24.5

16 D3M5Conc 2.6 0.7 27.8

17 D3M6Conc 2.3 0.8 33.5
57

7. Summary of Findings

This report relates the results obtained from the second comparison of concrete

rheometers. It was carried out in Cleveland (OH, USA) in May 2003. The first

comparison was held in France in October 2003 and the results are reported in Ref. [3].

A series of 23 mixtures was tested in five rheometers, two of which had the same design

(IBB and IBB portable). Seventeen mixtures were concrete and five were mortars (no

coarse aggregates added). The mixtures had slumps ranging from 121 mm to 248 mm,

with some of the concrete being SCC. The most important characteristic was that they

had a wide range of combinations of yield stress and plastic viscosity. Some tests using

oil, as the first attempt to develop a reference material, were also performed.

The rheometers were all rotational, but were based on different principles and had highly

different geometries. They could be grouped as follows:

• Coaxial: BML, CEMAGREF-ING

• Parallel plate: BTRHEOM

• Mixing action with an impeller: IBB and Two-Point apparatus

All the rheometers mentioned above were used in this Phase II with the exception of the

CEMAGREF-IMG. This rheometer, that was used in the first round-robin tests, could not

be included as part of this test program, because of transportation difficulties.

It was confirmed, as shown in the first round-robin [3], that the rheometers gave different

values of the Bingham constants of yield stress and plastic viscosity, even for those

instruments that give these directly in fundamental units. Some conclusions also

confirmed the findings of the first round-robin:

• The rank of mixtures with respect both yield stress and plastic viscosity was shown to

be not independent of the rheometer used. In quite a few cases at least 3 rheometers

position one mixture at the same rank.

• The degree of correlation of both yield stress and plastic viscosity measurements

between any pair of rheometers was reasonably high. Relationships with 95 %

confidence levels have been proposed to relate measurements with one rheometer to

those with another. Nevertheless, much research is needed to obtain a good

correlation function between any two rheometers. This can be seen as the correlation

functions, especially for viscosity, obtained at LCPC (Phase I) and at MB (Phase II)

are not the same.

• The slump test correlates well with the yield stress as measured with any of the

rheometers

• All rheometers could be used to estimate the flow characteristics of concrete as based

on the Bingham parameters.

Some new conclusions could also be drawn:

• The concept of relative viscosity first described in Ref. [30] could be used to compare

results from rheometers that do not provide results using the same units, as the

relative viscosity is independent of the geometry used.
58

• The measurements using oil were conducted in all rheometers with the exception of

the BTHREOM. This rheometer is not designed to measure a Newtonian fluid.

Although the correlation factor varied from 0.7 to 3, it could be conceived that some

benefit could be found in using oil as reference material. Obviously, it is clear that a

reference material should be granular in nature and cannot be pure oil.

• An attempt in determining the reproducibility of the results showed that small

variation in the concrete could cause large changes in the rheometers results. This

conclusion should be taken with some caution because of the limited data used for

this test.
59

8. Resolution of Phase I Recommendations and Recommendations for

Future work

This research was not able to answer some of the questions raised by the first round-robin

[3], and it is the general opinion of the authors that further research in this field is

warranted.

8.1. Resolution of Phase I Recommendations

Some of the tasks labeled as future work in the first round-robin were achieved in this

campaign. These tasks outlined in Phase I [3] and the corresponding achievements of this

test program are listed below:

• A wider range of mixtures, including self-consolidating concrete mixtures should be

tested: At least 3 mixtures prepared through this test program could qualify as SCC.

• Concrete mixtures with a wider range of plastic viscosities should be tested: As

shown in Figure 18 and Figure 19 this was achieved by preparing mixtures with both

high and low plastic viscosities.

• A set of repetition mixtures should be prepared to give a higher level of confidence in

the results: A level of repeatability was examined through the duplication of three

mixtures as shown in Section 6.3.

• Investigate the possibility of developing a standard material for calibration of

rheometers: The use of the oil was the first attempt to develop such a material.

• Others goal set by the first round robin were not addressed. For instance it was not

possible to have two sources of aggregates (crushed and round). On the other hand

these data could be used to validate some approaches to simulate the rheometers that

could be in progress in some laboratories.

8.2. Recommendations for Future Work

The following items are offered as recommendations for future work:

• More research is needed to understand the phenomena, which occur in rheometers

(segregation, slip, thixotropy), perturbing the rheological measurements. Once these

phenomena can be modeled, it will be possible to design better rheometers, able to

provide real values that can be securely used in the simulation of concrete casting.

• Numerical simulation of scale-1 concrete flow (e.g. the discharge of a 1-m3 bucket),

compared with experimental results, could be explored as another way of evaluating

the relevance of the various rheometers.

• The reference material issue was just approached here by using oil but it is by no

means resolved. Therefore, there is a need to develop a material that could be

properly characterized by independent means and that is granular in nature. Ideally,
60

oil with round aggregates with a distribution similar to concrete would be potentially

more appropriate. The oil viscosity would be easily characterized using a wellcalibrated rheometer for polymers and the influence of the addition of the aggregates

could be simulated using models [35] that could provide the change of viscosity due

to the aggregates. Even if the granular model suspension absolute viscosity could not

be measure, such a material could provide a reference material to compare all the

rheometers.

Of the research points raised above, the one that should be pursued immediately is the

reference material issue. The reason is that with a reliable reference material, calibration

of the rheometers could be seriously considered. As a first step, it is possible that the oil

used in this report could be satisfactory as the medium of a reference material. Also the

same manufacturer produces oils with lower and higher viscosities, if needed. But, the

question not yet answered is the source of the aggregates. The performances required by

the mixture are: aggregates and oil mixtures should be mixable using conventional

mixers; no significant sedimentation of the aggregates between mixing and during the

measurements should occur. Some ideas on aggregates characteristics could be: spherical,

same specific gravity as the oil (about 1) to avoid sedimentation, manufactured (constant

supply), and cheap and available in various sizes.

Using the grant available from ACI-CRC, a large quantity of an oil was purchased and an

experimental plan is under discussion to distribute and test the oil in the concrete

rheometers with and without aggregates. The rheometers that could participate in this

third round-robin are those presented here, but also others that were not present at Phase

II.

Finally, the authors of this report are launching a call for any suggestion for a suitable

aggregate.
61

9. References

1 Hu, C., “Rhéologie des bétons fluides,” Etudes et Recherches des Laboratoires

des Ponts et Chaussées, OA 16, 203 p., Paris, France, 1995

2 Ferraris C., Brower L., Ozyildirim C., Daczko J., “Workability of Selfcompacting Concrete,” Symp. Proc. of PCI/FHWA/FIB Int. Symposium on ‘High

Performance Concrete: The Economical Solution for Durable Bridges and

Transportation Structures,” Orlando (FL) Sept 25-27, pp. 398-407, 2000

3 Ferraris, C.F., and Brower, L.E. (Eds.). (2001). Comparison of concrete

rheometers: International tests at LCPC (Nantes, France) in October 2000,

(NISTIR 6819). Gaithersburg, MD. National Institute of Standards and

Technology.

4 Ferraris, C.F., “Measurement of the Rheological Properties of High Performance

Concrete: State of the Art Report,” Journal of Research of NIST, vol. 104 #5, pp.

461-478, 1999

5 Hackley V. A., Ferraris C. F., “Guide to Rheological Nomenclature:

Measurements in Ceramic Particulate Systems,” NIST Special Publication 946,

February 2001

6 Wallevik O.H., “The Rheology of Fresh Concrete and its Application on Concrete

with and without Silica Fume,” Dr.ing. thesis 1990:45, NTH Trondheim, p. 185

(in Norwegian), 1990

7 Wallevik O.H., Gjorv, O.E., “Development of a Coaxial Cylinder Viscometer for

Fresh Concrete,” Properties of Fresh Concrete, proceedings of the Rilem

Colloquium, Chapman & Hall, Hanover, October, 1990, pp. 213-224

8 de Larrard, F., Szitkar J.-C., Hu, C., Joly M., “Design of a Rheometer for Fluid

Concretes,” RILEM Workshop Special Concretes – Workability and Mixing, 201-

208, 1993

9 de Larrard, F., Sedran, T., Hu, C., Szitkar, J.C., Joly, M., Derkx, F., “Evolution of

the Workability of Superplasticized Concretes: assessment with BTRHEOM

Rheometer,” RILEM International Conference on Production Methods and

Workability of Concrete, RILEM Proceedings 32, Glasgow, Scotland, June 3-5,

pp. 377-388, 1996.

10 Beaupré, D., “Rheology of High Performance Shotcrete,” Ph. D. Thesis Uni. Of

British Columbia (Canada), 1994

11 Domone P.L.J., Xu Yongmo, Banfill P.F.G., “Developments of the Two-Point

Workability Test for High-Performance Concrete,” Magazine of Concrete

Research, vol. 51, pp. 181-190, 1999

12 Szecsy R E, “Concrete Rheology,” Ph.D thesis, University of Illinois at Urbana

Champaign, pp. 84-86, pp 205-209, 1997
62

13 Struble L, Puri U, and Ji X, “Concrete Rheometer,” Advances in Cement

Research 13(2) 53-63 (2001).

14 Powers, T.C. Properties of Fresh Concrete. New York: John Wiley & Sons, 1968

15 Leivo, M., “Rheological Modeling of the Compaction Properties of Concrete,”

H.-J. Wierig, Ed., Properties of Fresh Concrete, Proc. of the Coll. RILEM,

Chapman and Hall, 277-285, 1990

16 “Interim Guidelines for the Use of Self-Consolidating Concrete in

Precast/Prestressed Concrete,” Institute Member Plants, TR-6-03,

Precast/Prestressed Concrete Institute, 2003

17 “Recommendation for Construction of Self-Compacting Concrete”, Japan Society

of Civil Engineers, 1998

18 Tattersall, G.H., Banfill, P.F.G., The Rheology of Fresh Concrete, Pitman

Advanced Publishing Program, 1983

19 Wallevik O.H., The Rheology of Fresh Concrete and its Application on Concrete

with and without Silica Fume, Dr.ing. thesis 1990:45, NTH Trondheim. p.185 (in

Norwegian), 1990

20 Wallevik O.H., Gjorv, O.E., “Development of a Coaxial Cylinder Viscometer for

Fresh Concrete,” Properties of Fresh Concrete, proceedings of the Rilem

Colloquium, Chapman & Hall, Hanover, October, pp. 213-224, 1990

21 Wallevik, J. E. "Rheology of Particle Suspensions; Fresh Concrete, Mortar and

Cement Paste with Various Types of Lignosulfonates" (Ph.D.-thesis), Department

of Structural Engineering, The Norwegian University of Science and Technology,

pp.65-69, pp.195-204, 2003

22 Wallevik, J. E., "Rheological Measurements on a High Yield Value Bingham

Fluid with Low Agitation," Annual Transactions of the Nordic Rheology Society,

Friis, A. and Mason, S. L. (editors), Vomume 9, Trondheim, Norway, pp.39-44,

2001

23 de Larrard, F., Hu, C., Sedran, T., Szitkar, J.C., Joly, M., Claux, F., and Derkx, F.,

“A New Rheometer for Soft-to-Fluid Fresh Concrete,” ACI Materials Journal,

94(3), 234-243, 1997

24 de Larrard, F., Szitkar, J. C., Hu, C., Joly, M., “Design of a Rheometer for Fluid

Concretes,” P.J.M. Bartos, Ed., Proceedings, Special Concretes: Workability and

Mixing, Paisley, Scotland: RILEM, 201-208, 1993

25 Hu, C., deLarrard, F., Sedran, T., Bonlag, C., Bose, F., and Deflorenne, F.,

“Validation of BTRHEOM, the New Rheometer for Soft-to-fluid Concrete,”

Materials and Structures, 29(194), 620-631, 1996

26 Tattersall, G.H., The workability of concrete, A Viewpoint Publication, Cement

and Concrete Association ,1976
63

27 Beaupré, D., “Rheology of High Performance Shotcrete”, Ph. D. Thesis Uni. Of

British Columbia (Canada), 1994

28 Tattersall GH, Bloomer SJ, “Further Development of the Two-point Test for

Workability and Extension of its Range,” Magazine of Concrete Research 31:

202-210,1979

29 Domone PLJ, Xu Y, Banfill PFG, “Developments of the Two-point Workability

Test for High-performance Concrete,” Magazine of Concrete Research 51: 171-

179, 1999

30 Chiara F. Ferraris, Mette Geiker, Nicos S. Martys and Nicholas Muzzatti,

“Calibration of modified parallel-plate rheometer for measurement of suspensions

with a wide range of particle size”, to be submitted for publication

31 Private e-mail from Francois de Larrard and Thierry Sedran, 2004

32 Kendall, M.G., Rank Correlation Methods, Griffin, London, 1955

33 C. F. Ferraris, N. S. Martys, “Relating Fresh Concrete Viscosity Measurements

from Different Rheometers,” J. Res. Natl. Inst. Stand. Technol. 108, 2003

34 Hackley V. A, Ferraris C.F., "The Use of Nomenclature in Dispersion Science

and Technology" NIST Recommended Practice Guide, SP 960-3, 2001

35 Bullard J.W, Ferraris C.F., Garboczi E.J., Martys N., Stutzman P., “ Virtual

Cement,” Chapt 10.3 from “Innovations in Portland Cement Manufacturing”, Ed.

J.I. Bhatty, F.M. Miller, S.H. Kosmatka, PCA – CD-ROM, pp. 1311-1331, 2004
Table of content

Appendix A: Data from the Rheometers.................................................................. 3

DATA AND GRAPHS FROM THE BML .................................................................... 3

DATA AND GRAPHS FROM THE BTRHEOM ......................................................... 9

DATA AND GRAPHS FROM THE IBB .................................................................... 20

DATA AND GRAPH FROM THE IBB PORTABLE................................................. 26

DATA AND GRAPH FROM THE TWO-POINT TEST ............................................ 32

DATA AND GRAPH FROM THE UIUC RHEOMETER.......................................... 38

Disclaimer

The policy of the National Institute of Standards and Technology (NIST) is to use the

International System of Units (metric units) in its publications. This Appendix reproduces

reports written by the participants in the International tests in MBT. In some instances,

the use of the measurements units in these participants’ reports is not in full accordance

with NIST policy on SI Units. The copy in this appendix is reprinted in its original format

to preserve the integrity of the participants’ reports.
2
3

Appendix A: Data from the Rheometers

DATA AND GRAPHS FROM THE BML

Day 1, concrete

Torque Speed

(Nm) (rev/sec)

4,016 0,08 1

4,112 0,14 0

4,464 0,21 0

4,665 0,27 0

4,996 0,33 0

5,252 0,39 0

5,689 0,44 0

Torque Speed

(Nm) (rev/sec)

5,426 0,08 1

5,757 0,14 0

6,291 0,21 0

6,834 0,27 0

7,164 0,33 0

7,836 0,39 0

8,506 0,44 0

Torque Speed

(Nm) (rev/sec)

8,138 0,08 1

8,833 0,14 0

8,664 0,2 0

9,16 0,27 0

9,604 0,33 0

10,222 0,39 0

10,62 0,44 0

BLM-D1M3C - Concrete

BLM-D1M4C - Concrete

BLM-D1M4C - Concrete

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]
4

Day 2, concrete

Torque Speed

(Nm) (rev/sec)

9,351 0,08 0

9,901 0,14 0

10,076 0,21 0

10,147 0,27 0

11,054 0,33 0

11,837 0,39 0

12,201 0,44 0

Torque Speed

(Nm) (rev/sec)

1,148 0,08 1

1,325 0,14 0

1,563 0,2 0

1,819 0,27 0

2,12 0,33 0

2,442 0,39 0

2,819 0,44 0

Torque Speed

(Nm) (rev/sec)

1,328 0,08 0

2,185 0,14 0

3,006 0,21 0

3,92 0,27 0

5,005 0,33 1

6,052 0,39 1

7,967 0,45 1

BLM-D2M1C - Concrete

BLM-D2M2C - Concrete

BLM-D2M3C - Concrete

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]
5

Torque Speed

(Nm) (rev/sec)

1,383 0,08 1

1,891 0,14 0

2,323 0,21 0

2,884 0,27 0

3,454 0,33 0

4,101 0,39 0

4,965 0,44 1

Torque Speed

(Nm) (rev/sec)

2,289 0,08 1

3,056 0,14 0

3,912 0,2 0

4,681 0,27 0

5,618 0,33 0

6,613 0,39 0

8,071 0,44 1

Torque Speed

(Nm) (rev/sec)

2,025 0,08 1

2,777 0,14 0

3,544 0,2 0

4,137 0,27 0

5,063 0,33 0

6,214 0,39 0

7,27 0,44 1

BLM-D2M5C - Concrete

BLM-D2M7C - Concrete

BLM-D2M4C - Concrete

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]
6

Day 2, mortar

Torque Speed

(Nm) (rev/sec)

3,256 0,08 0

3,276 0,14 0

3,308 0,21 0

3,34 0,27 0

3,383 0,33 0

3,407 0,39 0

3,443 0,44 0

Torque Speed

(Nm) (rev/sec)

4,043 0,08 0

4,314 0,14 0

4,553 0,2 0

4,781 0,27 0

5,016 0,33 0

5,232 0,39 0

5,474 0,44 0

Torque Speed

(Nm) (rev/sec)

0,324 0,08 0

0,413 0,14 0

0,491 0,21 0

0,564 0,27 0

0,647 0,33 0

0,731 0,39 0

0,835 0,44 0

BLM-D2M1M - Mortar

BLM-D2M5M - Mortar

BLM-D2M6M - Mortar

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]
7

Day 3, concrete

Torque Speed

(Nm) (rev/sec)

4,825 0,08 0

5,156 0,14 0

5,359 0,21 0

5,73 0,27 0

6,151 0,33 0

6,565 0,39 0

7,267 0,44 1

Torque Speed

(Nm) (rev/sec)

1,781 0,08 0

2,486 0,14 0

3,024 0,2 0

3,436 0,27 0

4,322 0,33 0

5,039 0,39 0

6,093 0,44 1

Torque Speed

(Nm) (rev/sec)

4,621 0,08 0

5,069 0,14 0

5,781 0,2 0

6,286 0,27 0

7,033 0,33 0

7,654 0,39 0

8,511 0,44 1

BLM-D3M5C - Concrete

BLM-D3M6C - Concrete

BLM-D3M4C - Concrete

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]

0

4

8

12

0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]
8

Day 3, oil

Torque Speed

(Nm) (rev/sec)

0,67 0,08 0

1,04 0,14 0

1,41 0,20 0

1,78 0,27 0

2,15 0,33 0

2,51 0,39 0

2,84 0,44 0

Torque Speed

(Nm) (rev/sec)

0,67 0,08 0

1,05 0,14 0

1,42 0,20 0

1,79 0,27 0

2,15 0,33 0

2,52 0,39 0

2,85 0,44 0

Torque Speed

(Nm) (rev/sec)

0,67 0,08 0

1,04 0,14 0

1,42 0,20 0

1,79 0,27 0

2,16 0,33 0

2,52 0,39 0

2,85 0,44 0

BLM-D3O - Oil test 1

BLM-D3O - Oil test 2

BLM-D3O - Oil test 3

0

1

2

3

4

0,0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]

0

1

2

3

4

0,0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]

0

1

2

3

4

0,0 0,1 0,2 0,3 0,4 0,5

Rotational Velocity [rev/sec]

Torque [Nm]
9

DATA AND GRAPHS FROM THE BTRHEOM

Concrete Mixtures

Mixture BTRD1M2-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD1M3-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD1M4-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD1M5-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)
10

Mixture BTRD2M1-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD2M2-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD2M3-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD2M4-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)
11

Mixture BTRD2M5-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD2M7-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD3M1-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD3M2-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)
12

Mixture BTRD3M3-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD3M4-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD3M5-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD3M6-Concrete

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

 Mortar Mixtures
13

Mixture BTRD1M1-Mortar

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1 1.2

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD1M1-Mortar (2nd test)

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD1M2-Mortar

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD1M2-Mortar (Close-up)

2.2

2.25

2.3

2.35

2.4

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD2M1-Mortar

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD2M1-Mortar (Close-up)

1.96

1.97

1.98

1.99

2

2.01

2.02

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)
14

Mixture BTRD2M5-Mortar

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Mixture BTRD2M6-Mortar

0

1

2

3

4

5

6

7

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Oil

Oil

0

0.5

1

1.5

2

0 0.2 0.4 0.6 0.8 1

Rotational Velocity (rev/sec)

Torque (N-m)

Oil 1

Oil 2

Oil-empty bucket

Linear (Oil 1)
15

Concrete Mixtures

BTRD1M1C2.tst - Concrete BTRD1M2C2.tst - Concrete

Speed (rev/sec) Torque (N-m) Speed (rev/sec) Torque (N-m)

0.824 6.502

0.69 6.163

0.587 5.909

0.454 5.604

0.343 5.363

0.25 5.02

No Results

0 5.19

BTRD1M3C2.tst - Concrete BTRD1M4C2.tst - Concrete

Speed (rev/sec) Torque (N-m) Speed (rev/sec) Torque (N-m)

0.804 5.29 0.812 5.153

0.689 5.277 0.678 4.855

0.562 5.133 0.572 4.565

0.451 4.802 0.476 4.464

0.341 4.441 0.334 4.089

0.202 3.915 0.216 3.52

0.188 3.477 0.192 3.519

BTRD1M5C2.tst - Concrete BTRD2M1C2.tst - Concrete

Speed (rev/sec) Torque (N-m) Speed (rev/sec) Torque (N-m)

0.839 5.303 0.793 6.385

0.693 4.994 0.673 5.989

0.546 4.716 0.564 5.518

0.444 4.514 0.442 5.314

0.344 4.334 0.338 5.076

0.193 4.365 0 5.974

0.167 4.379 0.457 4.911

 * Point 6 is nonsense and was discounted for analysis

BTRD2M2C2.tst - Concrete BTRD2M3C2.tst - Concrete

Speed (rev/sec) Torque (N-m) Speed (rev/sec) Torque (N-m)

0.782 2.592 0.811 3.237

0.674 2.68 0.677 2.727

0.562 2.656 0.563 2.428

0.443 2.481 0.451 2.08

0.337 2.17 0.334 1.707

0.132 1.074 0.195 1.173

0.107 0.636 0.251 -0.024
16

BTRD2M4C2.tst - Concrete BTRD2M5C2.tst - Concrete

Speed (rev/sec) Torque (N-m) Speed (rev/sec) Torque (N-m)

0.796 3.377 0.798 3.272

0.677 3.368 0.704 2.855

0.563 3.268 0.564 2.456

0.447 3 0.453 2.114

0.327 2.609 0.333 1.686

0.224 2.01 0.179 0.833

0.249 1.349 0.176 0.577

BTRD2M7C2.tst - Concrete BTRD3M1C2.tst - Concrete

Speed (rev/sec) Torque (N-m) Speed (rev/sec) Torque (N-m)

0.832 3.192 0.813 5.246

0.7 2.697 0.675 4.818

0.579 2.362 0.58 4.52

0.438 2.01 0.452 4.092

0.336 1.672 0.358 3.722

0.177 1.061 0.227 2.952

0.291 0.576 0.308 2.736

BTRD3M2C2.tst - Concrete BTRD3M3C2-2.tst - Concrete

Speed (rev/sec) Torque (N-m) Speed (rev/sec) Torque (N-m)

0.796 1.762 0.819 5.813

0.678 1.784 0.687 5.43

0.614 1.985 0.58 5.063

0.451 1.732 0.458 4.762

0.317 1.475 0.325 4.369

0.24 1.059 0.206 3.909

0.213 0.896 0.747 2.969

 * Test was restarted after about 2 minutes

BTRD3M4C2.tst - Concrete BTRD3M5C2.tst - Concrete

Speed (rev/sec) Torque (N-m) Speed (rev/sec) Torque (N-m)

0.819 4.336 0.801 2.23

0.685 4.048 0.668 2.281

0.572 3.791 0.573 2.184

0.473 3.56 0.452 1.985

0.351 3.346 0.353 1.776

0.24 2.895 0.217 0.936

0.266 2.449 0.204 0.848
17

BTRD3M6C2.tst - Concrete

Speed (rev/sec) Torque (N-m)

0.807 3.9

0.692 3.471

0.573 3.356

0.456 3.197

0.27 2.916

0.183 2.807

0.156 2.606

Mortar Mixtures

BTRD1M1M2.tst - Mortar BTRD1M1M2.tst - 2nd mort tst

Speed (rev/sec) Torque (N-m) Speed (rev/sec) Torque (N-m)

1.031 6.711 0.808 3.287

0.697 2.486 0.729 3.013

0.755 3.768 0.486 3.08

0.857 3.641 0.457 2.337

0.511 4.289 0.456 1.716

0.447 4.859 0.525 1.105

0 4.023 0.412 0.709

* Could not attain a proper Bingham relationship * Could not attain a proper Bingham relationship

BTRD1M2M2.tst - Mortar BTRD2M1M2.tst - Mortar

Speed (rev/sec) Torque (N-m) Speed (rev/sec) Torque (N-m)

0.801 2.264 0.807 1.977

0.688 2.309 0.686 2.005

0.568 2.367 0.572 2.017

0.459 2.375 0.461 2.014

0.34 2.32 0.335 1.985

0.217 2.218 0.218 1.971

0.41 2.058 0.14 2.057

* Could not attain a proper Bingham relationship

BTRD2M5M2.tst - Mortar BTRD2M6M2.tst - Mortar

Speed (rev/sec) Torque (N-m) Speed (rev/sec) Torque (N-m)

0.812 2.557 0.795 1.471

0.698 2.26 0.683 1.431

0.572 1.998 0.57 1.325

0.455 1.825 0.453 1.198

0.328 1.75 0.335 1.041

0.214 1.641 0.189 0.788

0.074 1.567 0.221 0.505

Oil
18

Oil 1 (oil2.tst) Oil 2 (oil3.tst)

Speed (rev/sec) Torque (N-m) Speed (rev/sec) Torque (N-m)

0.825 1.894 0.836 1.619

0.688 1.807 0.697 1.37

0.574 1.676 0.568 1.346

0.461 1.6 0.455 1.417

0.334 1.539 0.333 1.629

0.202 1.445 0.192 1.628

0.554 1.331 0.202 1.571

Oil (oil5-empty.tst)

Speed (rev/sec) Torque (N-m)

0.806 0.367

0.68 0.444

0.573 0.489

 

 

 

 

* Test completed after oil was removed
19

 BTRHEOM: Summary of Mixtures & Results

Bingham

Parameters Torque vs. Rot. Velocity

Bingham Regression

Results Shear

Stress

Mixture Viscosity Reference

1

Average

Seal Test

Mean

Friction g

(N-m)

h

(N-m-s)

r

2 τo

(Pa)

μ

(Pa-s)

Comments

Concrete

BTRD1M1C 3.106 No results – concrete too stiff

BTRD1M2C 6.467 4.451 2.495 0.995 1235 110 Manually assisted movement

BTRD1M3C 5.075 3.622 2.338 0.991 1005 103

BTRD1M4C 6.244 3.112 2.583 0.967 864 114

BTRD1M5C 3.374 3.905 1.569 0.927 1084 69

BTRD2M1C 4.479 4.034 2.887 0.974 1120 127 Manually assisted movement; Based on 5 data pts

BTRD2M2C 6.076 1.168 2.269 0.751 324 100

BTRD2M3C 5.984 0.579 3.258 0.997 161 143

BTRD2M4C 5.768 1.767 2.317 0.852 491 102

BTRD2M5C 8.223 0.318 3.731 0.984 88 164 Manually assisted movement

BTRD2M7C 3.763 0.569 3.128 0.994 158 138

BTRD3M1C 6.689 2.264 3.790 0.980 628 167 Vibration used; vibration malfunction; test restarted2

BTRD3M2C 6.348 1.019 1.189 0.628 283 52 Segregation witnessed in concrete

BTRD3M3C 6.873 3.332 3.043 0.997 925 134 Vibration used; vibration malfunction; test restarted3

BTRD3M4C 6.252 2.414 2.385 0.986 670 105 Vibration malfunction4

BTRD3M5C 6.753 0.841 2.071 0.758 233 91

BTRD3M6C 4.476 2.474 1.610 0.958 687 71 Vibrated manually; manually assisted movement

Mortar

BTRD1M1M 5.19 2.673 2.261 0.119 742 100 No proper relationship

BTRD1M1M 0.473 3.381 0.353 131 149 BTRD1M1M retest; no proper relationship5

BTRD1M2M 6.268 2.284 0.049 0.032 634 2 No proper relationship

BTRD2M1M 6.724 1.983 0.023 0.067 550 1 No proper relationship

BTRD2M5M 3.560 1.241 1.489 0.939 345 66 Lumps in mortar

BTRD2M6M 4.924 0.637 1.134 0.960 177 50 “Soupy” mortar with balling

Oil

Oil 1 4.911 1.286 0.727 0.986 357 32 No vibration

Oil 2 1.600 -0.191 0.1078 444 -8 Oil Retest; no vibration

Oil – Empty

Bucket

0.795 -0.526 0.989 221 -23 Test completed after oil was removed

1

 Average of two tests

2

 Program malfunction - 30 to 40 seconds of varying vibration. Test restarted about 1 1⁄2 minutes after initially started. 3 Program malfunction – 30 seconds of proper vibration, 30 seconds of high freq. vibration. Test restarted about 2

minutes after initially started.

4

 Program malfunction – 30 seconds of proper vibration, 15 to 30 seconds of high freq. vibration. 5

 A seal was dislodged during testing. This likely caused the improper relationship
20

DATA AND GRAPHS FROM THE IBB

Concrete Mixtures

IBBD1M1C-T1

G=6,938; H=7,858

y = 0,1272x - 0,8819

R2

 = 0,9853

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD1M2C-T1

G=3,845; H=7,966

y = 0,1255x - 0,4828

R2

 = 0,9848

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD1M3C-T1

G=2,088; H=5,903

y = 0,1694x - 0,3535

R2

 = 0,9702

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD1M4C-T1

G=2,731; H=7,604

y = 0,1314x - 0,3584

R2

 = 0,9837

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD1M5C-T1

G=4,924; H=6,827

y = 0,1465x - 0,7212

R2

 = 0,9679

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD2M1C-T1

G=5,632; H=9,366

y = 0,1068x - 0,6021

R2

 = 0,9817

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD2M2C-T1

G=0,345; H=9,052

y = 0,1104x - 0,0379

R2

 = 0,9935

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD2M3C-T1

G=0,0 (-1,97); H=47,418

y = 0,021x + 0,0427

R2

 = 0,9745

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD2M4C-T1

G=0,746; H=17,501

y = 0,0572x - 0,0431

R2

 = 0,9976

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD2M5C-T1

G=0,733; H=26,517

y = 0,0378x - 0,0278

R2

 = 0,9992

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)
21

IBBD2M7C-T1

G=0,328; H=26,237

y = 0,0381x - 0,0123

R2

 = 0,9965

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD3M1C-T1

G=4,184; H=10,521

y = 0,095x - 0,3969

R2

 = 0,9937

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD3M2C-T1

G=0,66; H=8,037

y = 0,1243x - 0,082

R2

 = 0,9802

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD3M3C-T1

G=2,643; H=10,23

y = 0,0978x - 0,259

R2

 = 0,9853

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD3M4C-T1

G=1,39; H=6,267

y = 0,1596x - 0,222

R2 = 0,9808

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD3M5C-T1

G=0,529; H=18,161

y = 0,055x - 0,0285

R2

 = 0,9915

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD3M6C-T1

G=3,274; H=13,504

y = 0,0741x - 0,2431

R2

 = 0,9885

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

Mortar Mixtures

IBBD1M1M-T1

G=1,129; H=2,089

y = 0,4787x - 0,5401

R2

 = 0,9945

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD1M2M-T1

G=1,125; H=2,141

y = 0,4671x - 0,5257

R2

 = 0,9949

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)
22

IBBD2M1M-T1

G=1,186; H=1,953

y = 0,5117x - 0,6065

R2

 = 0,9938

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD2M5M-T1

G=2,069; H=5,779

y = 0,1731x - 0,3582

R2

 = 0,9995

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

OIL

IBBD3OIL-T1

G=0,0 (-0,333); H=10,024

y = 0,0998x + 0,0331

R2

 = 0,9999

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBBD3OIL-T2

G=0,0 (-0,328); H=10,033

y = 0,0997x + 0,0326

R2

 = 0,9999

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)
23

IBB Concrete mixtures Data

IBB-D1M1C IBB-D1M2C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

15.66 1.09 12.85 1.08

14.19 0.91 10.72 0.91

12.41 0.74 9.35 0.73

11.03 0.56 8.19 0.56

10.00 0.40 7.20 0.40

9.28 0.24 5.95 0.24

IBB-D1M3C IBB-D1M4C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

8.84 1.08 10.43 0.96

7.20 0.91 8.96 0.85

6.06 0.73 8.02 0.73

5.29 0.56 6.85 0.56

4.37 0.40 5.65 0.39

3.95 0.24 4.85 0.24

IBB-D1M5C IBB-D2M1C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

11.85 0.96 15.15 0.97

10.63 0.85 13.54 0.85

9.45 0.73 12.09 0.74

8.45 0.56 10.66 0.57

7.87 0.40 9.51 0.41

6.81 0.24 8.28 0.25

IBB-D2M2C IBB-D2M3C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

7.13 0.74 16.89 0.39

5.32 0.56 12.36 0.32

3.85 0.40 9.78 0.24

2.70 0.24
24

IBB-D2M4C IBB-D2M5C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

7.73 0.40 11.33 0.40

6.18 0.32 9.05 0.32

4.97 0.24 7.19 0.24

3.35 0.15 4.68 0.15

IBB-D2M7C IBB-D3M1C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

10.84 0.40 14.68 0.97

8.50 0.32 13.14 0.86

6.51 0.24 11.59 0.74

4.17 0.14 10.24 0.57

8.54 0.41

6.86 0.25

IBB-D3M2C IBB-D3M3C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

3.99 0.40 12.97 0.96

3.13 0.32 10.96 0.85

2.55 0.25 9.95 0.73

1.94 0.14 8.10 0.56

6.70 0.40

5.50 0.24

IBB-D3M4C IBB-D3M5C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

7.78 0.97 7.87 0.40

6.53 0.85 6.08 0.32

5.77 0.74 4.76 0.24

4.72 0.56 3.28 0.14

3.91 0.40

3.15 0.24

IBB-D3M6C 

Torque (Nm) Speed (rev/sec) 

8.73 0.39

7.37 0.32

6.53 0.24

5.27 0.14
25

IBB Mortar Mixtures Data

IBB-D1M1M IBB-D1M2M

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

3.45 1.09 3.50 1.09

3.04 0.92 3.07 0.91

2.63 0.74 2.66 0.74

2.25 0.57 2.28 0.56

1.96 0.40 1.96 0.40

1.71 0.24 1.71 0.24

IBB-D2M1M IBB-D2M5M

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

3.14 0.97 7.70 0.97

2.86 0.86 6.97 0.85

2.59 0.74 6.26 0.73

2.24 0.57 5.27 0.56

1.96 0.40 4.37 0.40

1.73 0.25 3.49 0.24

IBB-D3-OIL1 IBB-D3-OIL2

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

9.37 0.96 9.37 0.97

8.15 0.85 8.20 0.85

6.98 0.73 6.99 0.73

5.27 0.56 5.26 0.56

3.63 0.40 3.63 0.40

2.12 0.24 2.11 0.24
26

DATA AND GRAPH FROM THE IBB PORTABLE

Concrete Mixtures

IBPD1M1C-T1

G=7,161; H=10,013

y = 0,0999x - 0,7153

R2

 = 0,9959

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD1M2C-T1

G=5,339; H=8,688

y = 0,1151x - 0,6147

R2

 = 0,9885

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD1M3C-T1

G=3,219; H=7,441

y = 0,1345x - 0,4331

R2

 = 0,9854

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD1M4C-T1

G=3,898; H=9,112

y = 0,1098x - 0,4281

R2

 = 0,987

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD1M5C-T1

G=5,979; H=7,732

y = 0,1293x - 0,7724

R2

 = 0,9582

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD2M1C-T1

G=7,505; H=9,216

y = 0,1085x - 0,8138

R2

 = 0,985

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD2M2C-T1

G=1,249; H=11,288

y = 0,0886x - 0,1107

R2

 = 0,9941

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD2M3C-T1

G=0,0 (-1,575); H=37,672

y = 0,0265x + 0,0424

R2

 = 0,9899

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20 25 30

Torque (Nm)

Speed (rev/s)

IBPD2M4C-T1

G=0,727; H=25,377

y = 0,0394x - 0,0288

R2

 = 0,9985

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD2M5C-T1

G=0,686; H=30,349

y = 0,0329x - 0,0224

R2

 = 0,9868

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)
27

IBPD2M7C-T1

G=0,481; H=26,861

y = 0,0372x - 0,0175

R2

 = 0,9981

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD3M1C-T1

G=4,403; H=14,289

y = 0,0701x - 0,309

R2

 = 0,9893

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD3M2C-T1

G=0,781; H=9,416

y = 0,1062x - 0,083

R2

 = 0,9829

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD3M3C-T1

G=3,503; H=12,282

y = 0,0814x - 0,2845

R2

 = 0,989

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD3M4C-T1

G=2,725; H=6,862

y = 0,1457x - 0,397

R2

 = 0,9841

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD3M5C-T1

G=0,999; H=18,824

y = 0,0531x - 0,0529

R2

 = 0,9907

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD3M6C-T1

G=3,358; H=16,087

y = 0,0621x - 0,2082

R2

 = 0,9985

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

Mortar Mixtures

IBPD1M1M-T1

G=1,599; H=1,913

y = 0,5228x - 0,836

R2

 = 0,9902

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD1M2M-T1

G=1,457; H=2,066

y = 0,4836x - 0,7041

R2

 = 0,9959

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)
28

IBPD2M1M-T1

G=1,648; H=1,929

y = 0,5183x - 0,8542

R2

 = 0,9961

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD2M5M-T1

G=2,274; H=6,228

y = 0,1604x - 0,3645

R2

 = 0,9996

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD2M6M-T1

G=0,0 (-0,149); H=3,909

y = 0,2559x + 0,0382

R2

 = 0,9902

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

Oil

IBPD3OIL-T1

G=0,0 (-0,182); H=11,04

y = 0,0906x + 0,0166

R2

 = 0,9999

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)

IBPD3OIL-T2

G=0,0 (-0,17); H=11,027

y = 0,0907x + 0,015

R2

 = 0,9999

0

0,2

0,4

0,6

0,8

1

0 5 10 15 20

Torque (Nm)

Speed (rev/s)
29

DATA

IBP-D1M1C IBP-D1M2C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

15.23 0.80 12.48 0.80

13.91 0.66 10.86 0.65

12.24 0.52 9.37 0.51

10.56 0.37 8.55 0.36

9.57 0.23 7.59 0.23

8.33 0.10 6.15 0.10

IBP-D1M3C IBP-D1M4C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

9.49 0.80 11.39 0.80

7.81 0.66 9.93 0.65

6.81 0.51 8.11 0.51

5.98 0.37 6.98 0.36

4.84 0.23 6.07 0.23

4.18 0.10 5.03 0.09

IBP-D1M5C IBP-D2M1C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

12.63 0.80 15.08 0.80

10.61 0.65 13.47 0.66

9.59 0.51 11.94 0.51

8.49 0.36 10.96 0.37

7.76 0.23 9.24 0.23

7.20 0.09 8.80 0.09

IBP-D2M2C IBP-D2M3C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

8.21 0.61 21.82 0.61

6.02 0.44 14.13 0.44

4.17 0.27 8.14 0.27

2.80 0.12 3.77 0.12

IBP-D2M4C IBP-D2M5C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

16.28 0.61 19.57 0.61

11.56 0.44 13.34 0.44

7.58 0.27 8.42 0.27

3.96 0.12 5.12 0.12
30

IBP-D2M7C IBP-D3M1C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

16.95 0.61 16.59 0.82

12.01 0.44 13.49 0.67

7.61 0.27 11.53 0.52

3.98 0.12 9.72 0.37

7.70 0.24

6.29 0.11

IBP-D3M2C IBP-D3M3C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

6.62 0.61 13.81 0.80

4.58 0.44 11.17 0.66

3.62 0.28 9.46 0.51

1.94 0.12 7.86 0.37

6.53 0.23

4.82 0.09

IBP-D3M4C IBP-D3M5C

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

8.50 0.80 12.71 0.61

7.04 0.66 8.80 0.44

6.03 0.51 5.95 0.27

5.01 0.37 3.62 0.12

4.40 0.23

3.58 0.09

IBP-D3M6C 

Torque (Nm) Speed (rev/sec) 

13.10 0.61

10.31 0.44

7.94 0.27

5.23 0.12
31

Mortars mixtures

IBP-D1M1M IBP-D1M2M

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

3.18 0.80 3.15 0.80

2.84 0.66 2.78 0.65

2.53 0.51 2.46 0.51

2.24 0.37 2.19 0.36

2.03 0.23 1.93 0.23

1.87 0.10 1.69 0.10

IBP-D2M1M IBP-D2M5M

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

3.24 0.80 7.23 0.80

2.89 0.66 6.35 0.66

2.60 0.51 5.47 0.51

2.33 0.37 4.59 0.37

2.09 0.23 3.72 0.23

1.87 0.10 2.83 0.10

IBP-D2M6M 

Torque (Nm) Speed (rev/sec) 

3.09 0.80

2.38 0.66

1.74 0.51

1.18 0.36

0.73 0.23

0.38 0.10

IBB Portable Oil tests data

IBP-OIL1 IBP-OIL2

Torque (Nm) Speed (rev/sec) Torque (Nm) Speed (rev/sec)

8.68 0.80 8.68 0.80

7.05 0.66 7.05 0.66

5.44 0.51 5.43 0.51

3.82 0.37 3.81 0.36

2.30 0.23 2.30 0.23

0.92 0.10 0.95 0.10
32

DATA AND GRAPH FROM THE TWO-POINT TEST

♥ the recorded plastic viscosity values were low or negative for these mixes. The yield stress values were high (and

slumps relatively low) and we believe that during testing the air pockets created immediately behind the impeller

blades may not have refilled with concrete or mortar before the next pass of the blade, resulting in falsely low values of

torque at increasing impeller speed, and hence invalid plastic viscosity. There is sufficient confidence in the yield

stress values for their use in the subsequent analysis.

♠ negative recorded values for yield stress, which can be considered as zero.

MBT ref UCL test ref regression analysis output: oil pressure vs speed (voltages) Bingham constants

 idling (mean of two) concrete (after correction)

yield

stress

τ0

plastic

viscosity

μ

 intercept slope R2 intercept slope R2

g

(N·m)

h

(N·m·s)

(Pa) (Pa·s)

Concrete 

D1M1Conc TWOD1M1C 0.057 0.054 0.961 0.239 0.058 0.944 7.00 0.81 855 14

D1M2Conc TWOD1M2C 0.065 0.052 0.956 0.207 0.061 0.974 5.45 1.50 665 26

D1M3Conc TWOD1M3C 0.081 0.053 0.955 0.195 0.062 0.966 4.38 1.72 534 30

D1M4Conc TWOD1M4C 0.074 0.055 0.942 0.188 0.060 0.977 4.37 0.82 533 14

D1M5Conc TWOD1M5C 0.090 0.049 0.861 0.264 0.050 0.890 6.66 0.09 812 ♥

D2M1Conc TWOD2M1C 0.075 0.056 0.948 0.274 0.054 0.889 7.65 -0.38 933 ♥

D2M2Conc TWOD2M2C 0.099 0.050 0.884 0.142 0.067 0.952 1.63 3.13 198 54

D2M3Conc TWOD2M3C 0.101 0.052 0.949 0.127 0.103 0.963 1.00 9.46 121 163

D2M4Conc TWOD2M4C 0.096 0.056 0.885 0.102 0.087 0.990 0.24 5.68 30 98

D2M5Conc TWOD2M5C 0.067 0.057 0.950 0.119 0.094 0.951 2.01 6.81 245 117

D2M7Conc TWOD2M7C 0.069 0.057 0.967 0.102 0.091 0.960 1.27 6.19 155 107

D3M1Conc TWOD3M1C 0.064 0.057 0.943 0.171 0.065 0.977 4.14 1.55 505 27

D3M2Conc TWOD3M2C 0.065 0.054 0.945 0.080 0.069 0.984 0.58 2.67 71 46

D3M3Conc TWOD3M3C 0.060 0.056 0.969 0.151 0.073 0.980 3.50 3.15 427 54

D3M4Conc TWOD3M4C 0.067 0.054 0.964 0.163 0.068 0.907 3.69 2.53 451 44

D3M5Conc TWOD3M5C 0.059 0.055 0.940 0.087 0.077 0.990 1.07 4.04 130 70

D3M6Conc TWOD3M6C 0.062 0.056 0.941 0.119 0.079 0.982 2.19 4.37 268 74

 

Mortar 

D1M1Mort TWOD1M1M 0.077 0.050 0.932 0.121 0.049 0.987 1.70 -0.21 208 ♥

D1M2Mort TWOD1M2M 0.091 0.046 0.896 0.129 0.051 0.977 1.45 0.87 177 15

D2M1Mort TWOD2M1M 0.097 0.051 0.900 0.148 0.051 0.975 1.97 0.01 240 ♥

D2M5Mort TWOD2M5M 0.082 0.054 0.912 0.120 0.061 0.977 1.49 1.33 181 23

D2M6Mort TWOD2M6M 0.063 0.054 0.955 0.061 0.060 0.987 -0.06 1.12 0♠ 19

 

Oil 

TWOD3M7(oil) 0.079 0.053 0.924 0.061 0.068 0.983 -0.65 2.87 0♠ 49

TWOD3M7(oil)1 0.073 0.055 0.926 0.060 0.069 0.985 -0.48 2.57 0♠ 44

TWOD3M7(oil)2 0.075 0.058 0.913 0.065 0.070 0.981 -0.38 2.25 0♠ 39
33

Concrete Mixtures

Mix D1M1Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D1M2Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D1M3Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D1M4Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D1M5Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D2M1Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)
34

Mix D2M2Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D2M4Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D2M5Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D2M7Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D3M1Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D2M3Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)
35

Mix D3M2Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D3M3Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D3M4Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D3M5Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D3M6Conc

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)
36

Mortar Mixtures

Mix D1M1Mort

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D1M2Mort

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D2M1Mort

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D2M5Mort

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

Mix D2M6Mort

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)
37

Oil

D3M7(oil)

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

torque (volts)

concrete

idling (before)

idling (after)

D3M7(oil)1

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)

D3M7(oil)2

0

0.1

0.2

0.3

0.4

0.5

0.6

012345

speed (volts)

oil pressure (volts)

concrete

idling (before)

idling (after)
38

DATA AND GRAPH FROM THE UIUC RHEOMETER

Torque-rotational speed curve of silicone oil. Test 1

Shear stress-shear rate curve of silicone oil Test 1
39

Torque-rotational speed curve of re-tested silicone oil :Test 1 and 2 repeat

Shear stress-shear rate curve of retested silicone oil: Test 1 and 2 repeat

y = 1.379x - 0.9883

y = 1.1517x + 0.073

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00

Rotational speed (rps)

Torque (N.m)

test 1 test 2 Linear (test 2) Linear (test 1)

y = 331.78x + 19.675

y = 397.26x - 266.36

-500.00

0.00

500.00

1000.00

1500.00

2000.00

2500.00

3000.00

0.00 2.00 4.00 6.00 8.00 10.00

Shear rate(1/s)

Shear stress (Pa)

test 1 test 2 Linear (test 1) Linear (test 2)
40

Table 1 Torque data of silicone oil, Test 1

Shear stress (Pa) 759.89 1088.83 1417.77 1746.71 2075.65 0.2922 0.6748

Table 2 Torque data of retested silicone oil: Test 1 and test 2 repeat

Rotational Speed (rpm) 20 30 40 50 60

Rotational Speed (rad/s) 2.09 3.14 4.19 5.24 6.28

Shear Rate (1/s) 2.61 3.92 5.23 6.53 7.84

Test 1 torque lb.in 14.33 38.36 50.42 47.72 62.08

Test 1 torque N·m 1.65 4.41 5.80 5.49 7.14 T= dT/dΩ=

Test 1 Shear stress (Pa) 886.48 1319.89 1753.29 2186.69 2620.10 0.073 1.1517

Test 2 torque lb·in 11.60 32.83 47.72 50.42 65.59

Test 2 torque N·m 1.33 3.78 5.49 5.80 7.54 T= dT/dΩ=

Test 2 Shear stress (Pa) 771.52 1290.46 1809.40 2328.34 2847.28 -0.9883 1.379

Rotational Speed

(rpm) 20 30 40 50 60

Rotational Speed

(rad/s) 2.09 3.14 4.19 5.24 6.28

Shear Rate (1/s) 2.61 3.92 5.23 6.53 7.84

Torque N·m 1.69 2.45 3.13 3.75 4.573 T= dT/dΩ=