measuring rheological properties of fresh mortars … measuring rheological properties of fresh...
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MEASURING RHEOLOGICAL MEASURING RHEOLOGICAL MEASURING RHEOLOGICAL
PROPERTIES OF FRESH PROPERTIES OF FRESH PROPERTIES OF FRESH
MORTARS WITH CONCRETE MORTARS WITH CONCRETE MORTARS WITH CONCRETE
RHEOMETERSRHEOMETERSRHEOMETERSAndraž Hočevar, Franci Kavčič, Igmat d.d.
Violeta Bokan Bosiljkov, UL FGG
University of LjubljanaFaculty of Civil and Geodetic Engineering
"Rheology of Building Materials", Regensburg, March, 12-13, 2014 2 | 20
OUTLINEOUTLINEOUTLINE
Motive
Rheometers
Test program
Results
Conclusions
"Rheology of Building Materials", Regensburg, March, 12-13, 2014 3 | 20
MOTIVEMOTIVEMOTIVE
Design process of concrete mixture can be time and
raw materials consuming
Concrete rheometers demand high volume of fresh
concrete
Tests on corresponding mortar
Concrete equivalent mortar (CEM) method
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MOTIVEMOTIVEMOTIVE
Aim of this presentation is to show pluses and
minuses of smaller measuring systems
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RHEOMETERSRHEOMETERSRHEOMETERS
ConTec Viscometer 5
Outer cylinder radius, Ro = 100 mm
Inner cylinder radius, Ri = 85 mm
Height of the cylinder is measured, (h ≈ 85 mm)
"Rheology of Building Materials", Regensburg, March, 12-13, 2014 6 | 20
RHEOMETERSRHEOMETERSRHEOMETERS
ConTec Viscometer 5
Outer cylinder radius, Ro = 100 mm
Inner cylinder radius, Ri = 85 mm
Height of the cylinder is measured, (h ≈ 85 mm)
"Rheology of Building Materials", Regensburg, March, 12-13, 2014 7 | 20
RHEOMETERSRHEOMETERSRHEOMETERS
ICAR Rheometer
Outer cylinder radius, Ro = 74 mm
Inner cylinder radius, Ri = 64 mm
Height of the cylinder, h = 127 mm
"Rheology of Building Materials", Regensburg, March, 12-13, 2014 8 | 20
RHEOMETERSRHEOMETERSRHEOMETERS
ICAR Rheometer
Outer cylinder radius, Ro = 74 mm
Inner cylinder radius, Ri = 64 mm
Height of the cylinder, h = 127 mm
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TEST PROGRAMTEST PROGRAMTEST PROGRAM
26 mortars from ordinary concrete and 12 mortars from SCC
mixtures
Rheology and slump flow with equipment for flow table spread
of mortar (SIST EN 1015-3:2001)
Mixing procedure (5 min):
Dry constituents - 1 min
Half of the water, 0.3 l of water with diluted liquid
admixtures, rest of the water - 1 min (while mixing)
Mixing for another - 3 min
"Rheology of Building Materials", Regensburg, March, 12-13, 2014 10 | 20
TEST PROGRAMTEST PROGRAMTEST PROGRAM
Measuring procedure:
Enlarged version of standard mortar mixer
Each mixture mixed once
Average of 3 repetitions
Remixed with flat rod before each measurement
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TEST PROGRAM TEST PROGRAM TEST PROGRAM --- mixturesmixturesmixtures
------3,1922,1281,064GGBS (kg)
---102406203---Silica fume (g)
224896448------Tuff (g)
27,7226,8827,4416,6816,3416,5710,8610,9811,09Superplastizicer (g)
2,9322,9322,9322,9322,9322,9322,9322,9322,932Water (kg)
13,03213,03213,03213,03213,03213,03213,03213,03213,032Aggregate – 0/2 (kg)
5,324,485,045,465,045,322,243,364,48CEM I 42,5 R (kg)
MT1CMT1BMT1AMM1CMM1BMM1AMZ1CMZ1BMZ1A
---11,208,405,60---Stabilizer (g)
------2,803,362,24Air entrainer (g)
------5,605,605,60Superplasticizer (g)
3,4283,2623,0983,5883,5883,5882,9322,9322,932Water (kg)
13,03213,03213,03213,03213,03213,03213,03213,03213,032Aggregate – 0/2 (kg)
------5,605,605,60CEM II/A-M (LL-S) 42,5 R (kg)
5,605,605,605,605,605,60---CEM I 42,5 R (kg)
MV1CMV1BMV1AMG1CMG1BMG1AMRA1CMRA1BMRA1A
16,811,25,6-16,811,25,6-Superplasticizer (g)
2,9322,9322,9322,9322,9322,9322,9322,932Water (kg)
13,03213,03213,03213,03213,03213,03213,03213,032Aggregate – 0/2 (kg)
----5,605,605,605,60CEM II/A-M (LL-S) 42,5 R (kg)
5,605,605,605,60----CEM I 42,5 R (kg)
ML1CML1BML1AML1MR1CMR1BMR1AMR1
MORTARS FROM ORDINARY CONCRETE
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TEST PROGRAM TEST PROGRAM TEST PROGRAM --- mixturesmixturesmixtures
99,2699,2699,2699,2699,26Superplasticizer – polyphosponic (g)
3,0323,0323,0323,0323,032Limestone filler (kg)
13,40513,40513,40513,40513,405Aggregate – 0/2 (kg)
3,0522,7722,8422,9282,912Water (kg)
5,605,605,605,605,60CEM I 42,5 R (kg)
MR4DMR4CMR4BMR4AMR4
19,6016,8014,0011,205,60--Stabilizer - powder (g)
39,2045,7250,6255,5260,4260,4260,42Superplasticizer (g)
-0,9321,6312,3323,0323,0323,032Limestone filler (kg)
14,83614,23213,77813,32612,88613,47014,052Aggregate - 0/2 (kg)
3,2483,2483,2483,2483,2482,9122,576Water (kg)
5,605,605,605,605,605,605,60CEM I 42,5 R (kg)
MM4MM3MM2MM1MR3MR2MR1
MORTARS FROM SCC
"Rheology of Building Materials", Regensburg, March, 12-13, 2014 13 | 20
TEST PROGRAMTEST PROGRAMTEST PROGRAM
Calculation of fundamental results Shear thickening behavior observed Bingham model on bottom 4 points
−
=
i
o
oi
R
Rh
RRT
ln4
1122
0
π
τ
SRRhoi
111
8
1222
−=
πµ
T = intersectionS = slope
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RESULTS RESULTS RESULTS ––– mixmixmix bybyby mixmixmix
Yield values – ordinary mortars
Lines are parallel Bigger difference between rheometers at higher values
Repeatability is better for ConTec
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RESULTS RESULTS RESULTS ––– mixmixmix bybyby mixmixmix
Plastic viscosity – ordinary mortars Lines are parallel, values almost identical
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RESULTS RESULTS RESULTS ––– mixmixmix bybyby mixmixmix
Yield value – SCC mortars
ICAR has zero values!
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RESULTS RESULTS RESULTS ––– mixmixmix bybyby mixmixmix
Plastic viscosity – SCC mortars
Lines are parallel, values almost identical
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RESULTS RESULTS RESULTS ––– correlationcorrelationcorrelation ofofof
rheometersrheometersrheometers
Ordinary mortar
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RESULTS RESULTS RESULTS ––– correlationcorrelationcorrelation ofofof
rheometersrheometersrheometers
SCC mortarAs expected correlation for yield values is not OK
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AdditionalAdditionalAdditional analysisanalysisanalysis
Analysis of variance: Change of mix design is statistically significant
with 5% risk for both rheological parameters Except for ICAR rheometer measuring yield
values of SCC mortar
Post hoc tests (Duncan, Bonferroni) tell us that ICAR has bigger variances inside measurements
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ZERO VALUES ZERO VALUES ZERO VALUES ––– WHY?WHY?WHY?
Is ICAR sensitive enough for measuring mortar?
Shear rate?
[1]
Small container gives us bigger shear rate!
Big vane in small container! Secondary flows?
[1] Feys, D., Verhoeven, R., De Schutter, G. 2007. Evaluation of time independent rheological models applicable to fresh self-compacting concrete. Applied Rheology 17, 5, 56244: 1-10.
Ω−
+=
22
22
io
io
RR
RRγ&
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CONCLUSIONSCONCLUSIONSCONCLUSIONS
In analysis we observe similar trends for both rheometers, except for yield values of SCC mortars.
ICAR Rheometer is not suitable for measuring too liquid mortars.
Further development is needed – container and vane size should be decreased proportionally, change theshape of vane.
Measurements should be done with appropriate shear rates.
THANK YOU FOR YOUR THANK YOU FOR YOUR THANK YOU FOR YOUR
ATTENTION!ATTENTION!ATTENTION!
University of LjubljanaFaculty of Civil and Geodetic Engineering