Mortar rheology
Transcript of Mortar rheology
Rheology of fresh concreteInfluence of superplasticizers
dr. Luka Zevnik, Vesna Jereb
Regensburg 2013
Air-migration The undesirable condition in which entrapped air in fresh SCC migrates tothe top surface causing a bubbling or boiling appearance. This is an indication of unstable airand a low viscosity mortar. Air-popping is another term used for this occurrence.
Bleeding The water that appears to rise to the surface of concrete subsequent toplacement. ACI defines bleeding as “the autogenous flow of mixing water within, or itsemergence from, newly placed concrete or mortar; caused by settlement of solid materialswithin the (concrete) mass.”
Blocking The condition in which coarse aggregate particles combine to form elementslarge enough to obstruct flow of the fresh concrete between reinforcing steel or otherobstructions in the concrete formwork. This property is of increased importance in SCCbecause of the absence of vibration energy to dislodge these blockages.
Cohesiveness The tendency of SCC to stick together, resulting in resistance to segregation,aggregate settlement, and bleeding.
Dynamic stability The characteristic of a fresh SCC mix that ensures uniform distributionof all solid particles and air voids as the SCC is transported and placed.
Filling ability The ability of SCC to flow under its own weight (without vibration) into andfill completely all spaces within formwork containing obstacles such as reinforcement.
Finishability The ease with which SCC can be finished to achieve the desired surfaceflatness and smoothness on that portion of an element that must be finished. Finishabilitydoes not refer to formed surface finish quality.
Passing ability The ability of SCC to flow through openings approaching the size of the mix s nominal max size aggregate without segregation or aggregate blocking
Pumpability The ability to pump without significant degradation of fresh concrete properties.
Sumpflow t500Stability the ability of fresh SCC to remain homogeneous during mixing, transportation, handling, placement, finishing, curing.
Static stability The charactaristic of concrete to maintain a uniform distribution of all solid particles and air voids once all
placement operation are complete. Stickiness Adherance to finishing tools
ViscosityWater sensitivity The amount of free water variation witin the mixture change the stability (and other SCC properties) of concrete from accaptable to unaccaptable range.
Introduction
Definitions and terms Relating to SCC [http://www.na.graceconstruction.com/custom/concrete/downloads/tb_1501b.pdf]
• How could we evaulte superplasticizer influence on concrete rheology(robustness etc…)?
Numerous investigations on job sites, and long term use in practice• Is there any other option?• Could we predict the concrete rheology with mortar or paste
experiments?
Superplasticizer influence on concrete rheology
Concrete Mortar PasteCEqM MEqP
Superplasticizer influence on concrete rheology
020406080
100% (dry solids)/powder mat.
consistency loss
robustness
min. powder content/m3
water reductionlow critical shear rate
low shear thickening
low concr. viscosity
static seggreg. resistence
0,50 0,45 0,40 0,35 0,30 0,25 0,20 0,15
water/powder
pote
ntial
pro
ble
ms
with c
oncre
te rheo
logy
Flowable concrete, SCC, HPCC30/37 S4C25/30 S3
0,50 0,45 0,40 0,35 0,30 0,25 0,20 0,15
water/powder
pote
ntial
pro
ble
ms
with c
oncre
te rheo
logy
Flowable concrete, SCC, HPCC30/37 S4C25/30 S3
Normal use of usual PCE...
Superplasticizer influence on concrete rheology
0,40 0,35 0,30 0,25
PCE 3
PCE 2
water/powder
pote
ntial
pro
ble
ms
with c
oncre
te rheo
logy
Flowable concrete, SCC, HPCC30/37 S4C25/30 S3
PCE 1
Superplasticizer influence on concrete rheology
Concrete rheology evaluation
Important rheological concrete parameters
Cohesivity
Bleeding
Seggregation at rest
Seggregation at pumping
Slump shape
Sound at mixing (air content)
Most advanced concrete rheometer
My collegue Vlado10.000+ concrete mixes
Concrete rheology evaluation – standard investigations
Concrete PCE Concrete Ph
CEM II A-M (LL-S) 42,5R 420 kg 420 kg
Limestone filler 90 kg 90 kg
Crushed aggregate 0/2, Soča 842 kg 842 kg
Natural aggregate 4/8, Soča 258 kg 258 kg
Natural aggregate 8/16, Soča 592 kg 592 kg
w/c 0,44 0,44
Air content 1,6 % 2 %
PCE (dry content) 0,21% /
Ph (dry content) / 0,63%
Cohesivity Slumpflow, t500 V - funnel
Concrete PCE Concrete Ph
CEM II A-M (LL-S) 42,5R 420 kg 420 kg
Limestone filler 90 kg 90 kg
Crushed aggregate 0/2, Soča 842 kg 842 kg
Natural aggregate 4/8, Soča 258 kg 258 kg
Natural aggregate 8/16, Soča 592 kg 592 kg
w/c 0,44 0,44
Air content 1,6 % 2 %
PCE (dry content) 0,21% /
Ph (dry content) / 0,63%
flow 680 mm 670 mm
t500 4,0s 2,2s
V funnel 9,3 s 6,5 s
L box (H1/H2) 91% 89%
cohesivity ***** *****
Overall filing Quite good Good
Concrete rheology evaluation – standard investigations
Mortar PCE Mortar Ph
CEM II A-M (LL-S) 42,5R
600 g 600 g
Limestone filler 177 g 177 g
Quartz sand 0-1 775 g 775 g
Quartz sand 0,5-1 87 g 87 g
w/c 0,475 0,480
Air content 2% 2%
PCE 0,24% /
Ph / 0,65%
Mortar rheology – standard investigations
Cohesivity- mortar Slumpflow - mortar
Mortar PCE Mortar Ph
CEM II A-M (LL-S) 42,5R
600 g 600 g
Limestone filler 177 g 177 g
Quartz sand 0-1 775 g 775 g
Quartz sand 0,5-1 87 g 87 g
w/c 0,475 0,480
Air content 2% 2%
PCE 0,24% /
Ph / 0,65%
flowminicone 39,5 cm 36,5 cm
t 250 4,7 s 2,6 s
t final 50 s 20,5 s
Cohesivity ***** *****
Overall filing Bad Very good
Mortar rheology – standard investigations
Vogel [Ein Messezell fur Specialmortel, www.vogel-labor.de]type measuring body. [www.schleibinger.com]
Rheology of mortar =Viscomat NT + Vogel cell
Calibration (TKK)
γ/N = 0,447 [min]/[s] γcrit-/(το /ηpl) = 0,321
cK = 0,868 τ/T = 0,76 [Pa]/[mNm]
0 1 2 3 40
10
20
30
40
50
60
70
N (R
PM)
time (min)
A typical speed profile.
Mortar rheology – rheological experiments
Mortar SCC and Mortar Ph
0 5 10 15 20 250
50
100
150
200
250
τ (P
a)
γ (1/s)
mortar PCE mortar Ph
0,1 1 10
6
10
100
mortar PCE mortar Ph
η (P
as)
γ (1/s)
Mortar rheology – rheological experiments
γ = 10 1/s γ = 1 1/s γ = 0,1 1/s
0 5 10 15 20 250
50
100
150
200
250
τ (P
a)
γ (1/s)
mortar PCE mortar Ph
0,1 1 10
6
10
100
mortar PCE mortar Ph
η (P
as)
γ (1/s)
parameter Mortar PCE Mortar Ph
γcrit 7 s-1 11 s-1
η@γcrit = (min. η) 8,5 Pas 6,2 Pas
Shear thinning [η@0,1]/[η@1] 1,7 4,2
Shear thinning [η@1]/[η@γcrit] 1,35 2,3
Shear thickening [η@γcrit]/[η@20]
0,625 0,87
Mortar rheology – rheological experiments
0 5 10 15 20 250
50
100
150
200
250
τ (P
a)
γ (1/s)
mortar PCE mortar Ph
0,1 1 7 10
6
10
100
mortar PCE mortar Ph
η (P
as)
γ (1/s)
parameter Mortar PCE Mortar Ph
γcrit 7 s-1 11 s-1
η@γcrit = (min. η) 8,5 Pas 6,2 Pas
Shear thinning [η@0,1]/[η@1] 1,7 4,2
Shear thinning [η@1]/[η@γcrit] 1,35 2,3
Shear thickening [η@γcrit]/[η@20]
0,625 0,87
Mortar rheology – rheological experiments
0 5 10 15 20 250
50
100
150
200
250
τ (P
a)
γ (1/s)
mortar PCE mortar Ph
0,1 1 10
6
10
100
mortar PCE mortar Ph
η (P
as)
γ (1/s)
parameter Mortar SCC Mortar Ph
γcrit 7 s-1 11 s-1
η@γcrit = (min. η) 8,5 Pas 6,2 Pas
Shear thinning [η@0,1]/[η@1] 1,7 4,2
Shear thinning [η@1]/[η@γcrit] 1,35 2,3
Shear thickening [η@γcrit]/[η@20]
0,625 0,87
Mortar rheology – rheological experiments
0 5 10 15 20 250
50
100
150
200
250
τ (P
a)
γ (1/s)
mortar PCE mortar Ph
0,1 1 10
6
10
100
mortar PCE mortar Ph
η (P
as)
γ (1/s)
parameter Mortar SCC Mortar Ph
γcrit 7 s-1 11 s-1
η@γcrit = (min. η) 8,5 Pas 6,2 Pas
Shear thinning [η@0,1]/[η@1] 1,7 4,2
Shear thinning [η@1]/[η@γcrit] 1,35 2,3
Shear thickening [η@γcrit]/[η@20]
0,625 0,87
Mortar rheology – rheological experiments
0 5 10 15 20 250
50
100
150
200
250
τ (P
a)
γ (1/s)
mortar PCE mortar Ph
0,1 1 10
6
10
100
mortar PCE mortar Ph
η (P
as)
γ (1/s)
parameter Mortar SCC Mortar Ph
γcrit 7 s-1 11 s-1
η@γcrit = (min. η) 8,5 Pas 6,2 Pas
Shear thinning [η@0,1]/[η@1] 1,7 4,2
Shear thinning [η@1]/[η@γcrit] 1,35 2,3
Shear thickening [η@γcrit]/[η@20]
0,625 0,87
Mortar rheology – rheological experiments
0,1 1 10
6
10
100
mortar PCE mortar Ph
η (P
as)
γ (1/s)
parameter Mortar SCC Mortar Ph
γcrit 7 s-1 11 s-1
η@γcrit = (min. η) 8,5 Pas 6,2 Pas
Shear thinning [η@0,1]/[η@1] 1,7 4,2
Shear thinning [η@1]/[η@γcrit] 1,35 2,3
Shear thickening [η@γcrit]/[η@20]
0,625 0,87
0 5 10 15 20 250
50
100
150
200
250
τ (P
a)
γ (1/s)
mortar PCE mortar Ph
Mortar rheology – rheological experiments
Mortar PCE Mortar Ph
flowminicone 39,5 cm 36,5 cm
t 250 4,7 s 2,6 s
t final 50 s 20,5 s
Cohesivity ***** *****
Overall filing Bad Very good
γcrit 7 s-1 11 s-1
η@γcrit = (min. η) 8,5 Pas 6,2 Pas
Shear thinning [η@0,1]/[η@1]
1,7 4,2
Shear thinning [η@1]/[η@γcrit]
1,35 2,3
Shear thickening [η@γcrit]/[η@20]
0,625 0,87
Mortar rheology – standard vs. Vogel rheology
Stand. e xp.
Vogel rh eology
Paste rheology – standard experiments
Paste PCE Paste Ph
CEM II A-M (LL-S) 42,5R
600 g 600 g
Limestone filler 177 g 177 g
w/c 0,45 0,45
PCE 0,24% /
Ph / 0,65%
flowminicone 29,5 cm 26,5 cm
Cohesivity ? ?
Overall filing ?? ??
parameter Paste PCE Paste Ph
γcrit 4,3 s-1 12 s-1
η@γcrit = (min. η) 0,89 Pas 1,09 Pas
Shear thinning [η@0,1]/[η@1] 2,26 4,85
Shear thinning [η@1]/[η@γcrit] 1,29 3,7
Shear thickening [η@γcrit]/[η@20]
0,58 0,77
0 5 10 15 20 250
5
10
15
20
25
30
35
τ (P
a)
γ (1/s)
paste PCE paste Ph
0,1 1 100,1
1
10
η (Pas
)
γ (1/s)
paste PCE paste Ph
Paste rheology – rheological experiments
Paste rheology vs. Mortar rheology
parameter Paste PCE
Paste Ph
γcrit 4,3 s-1 12 s-1
η@γcrit = (min. η) 0,89 Pas 1,09 Pas
Shear thinning [η@0,1]/[η@1] 2,26 4,85
Shear thinning [η@1]/[η@γcrit] 1,29 3,7
Shear thickening [η@γcrit]/[η@20]
0,58 0,77
0,1 1 100,1
1
10
η (Pas)
γ (1/s)
paste PCE paste Ph
parameter Mortar SCC
Mortar Ph
γcrit 7 s-1 11 s-1
η@γcrit = (min. η) 8,5 Pas 6,2 Pas
Shear thinning [η@0,1]/[η@1] 1,7 4,2
Shear thinning [η@1]/[η@γcrit]
1,35 2,3
Shear thickening [η@γcrit]/[η@20]
0,625 0,870,1 1 10
6
10
100
mortar PCE mortar Ph
η (P
as)
γ (1/s)
Concrete rheology vs. Mortar rheology
Concrete PCE
Concrete Ph
flow 680 mm 670 mm
t500 4,0s 2,2s
V funnel 9,3 s 6,5 s
cohesivity ***** *****
Mortar PCE Mortar Ph
flow 395 mm 365 mm
t250 4,7s 2,6s
t final 50 s 20,5 s
cohesivity ***** *****
γcrit 7 s-1 11 s-1
η@γcrit = (min. η) 8,5 Pas 6,2 Pas
Shear thinning [η@0,1]/[η@1]
1,7 4,2
Shear thinning [η@1]/[η@γcrit]
1,35 2,3
Shear thickening [η@γcrit]/[η@20]
0,625 0,87
PCE (pure) superplasticizers: Mortar rheology
0,1 1 10
10
100
PCE 1 PCE 2 PCE 3
η (Pas
)
γ (s-1)
parameter PCE 1 PCE 4 PCE 1 PCE 2 PCE 3
Mortar 1: agg. Size 0-1mm, w/c=0,475 Mortar 0: agg. Size 0-2mm, w/c=0,50
Flow 39,5 cm 37 cm 37 cm 33,5 cm 35 cm
Dosage (dry solids) 0,24 % 0,35 % 0,24 % 0,32 % 0,36 %
γcrit 7 s-1 7,5 s-1 10,2 s-1 10 s-1 10,6 s-1
η@γcrit = (min. η) 8,5 Pas 6,6 Pas 7,6 Pas 10,7 Pas 8,5 Pas
Shear thinning [η@0,1]/[η@1]
1,7 2,5 3,0 3,50 3,53
Shear thinning [η@1]/[η@γcrit]
1,34 1,72 1,76 1,87 2,04
Shear thickening [η@γcrit]/[η@20]
0,63 0,75 0,85 0,87 0,87
0,1 1 10
10
100
PCE 1 PCE 4
η (Pas
)
γ (1/s)
Superplasticizer formulations: mortar rheology
Mortar No
PCE 1 LSb w/c Flow Cohesivity
Bleeding
Seggreg
Overall filling
1 0,24% 0,00% 0,475 43 cm ***** *** *** very bad
2 0,24% 0,09% 0,50 44,5 cm ***** *** *** bad3 0,24% 0,18% 0,50 42,5 cm ***** *** *** ok4 0,24% 0,27% 0,50 39 cm ***** *** *** good5 0,24% 0,36% 0,53 40,5 cm ***** *** *** excelen
t
0 2 4 6 8 100
10
20
30
40
50
60
70
80
LS 0% w/c=0,475 LS 0,09% w/c=0,50 LS 0,18% w/c=0,50 LS 0,27% w/c=0,50 LS 0,36% w/c=0,525
τ (P
a)
γ (1/s)0,1 1 7 10
5
10
15
20
25
30 LS 0% w/c=0,475 LS 0,09% w/c=0,50 LS 0,18% w/c=0,50 LS 0,27% w/c=0,50 LS 0,36% w/c=0,525
η (Pas
)
γ (1/s)
parameter Mortar 1 Mortar 2 Mortar 3 Mortar 4 Mortar 5w/c 0,475 0,50 0,50 0,50 0,53PCE (dry solids) 0,24% 0,24% 0,24% 0,24% 0,24%LS (dry solids) 0,00% 0,09% 0,18% 0,27% 0,36%Flow (minicone) 43 cm 44,5 cm 42,5 cm 39 cm 40,5 cmCohesivity ***** ***** ***** ***** *****Bleeding *** *** *** *** ***Segregation *** *** *** *** ***Overall filling very bad bad ok good excellent
γcrit 4 s-1 8 s-1 7,4 s-1 9,1 s-1 11 s-1
η@γcrit = (min. η)
6,6 Pas 3,8 Pas 5 Pas 4,8 Pas 3,8 Pas
Shear thinning [η@0,1]/[η@1]
1,34 1,30 1,75 2,39 2,52
Shear thinning [η@1]/[η@γcrit]
1,12 1,31 1,58 1,81 1,95
Shear thickening [η@γcrit]/[η@20]
0,61 0,72 0,72 0,85 0,90
Superplasticizer formulations: mortar rheology
parameter Mortar 1 Mortar 2 Mortar 3 Mortar 4 Mortar 5
w/c 0,475 0,50 0,50 0,50 0,53PCE (dry solids) 0,24% 0,24% 0,24% 0,24% 0,24%LS (dry solids) 0,00% 0,09% 0,18% 0,27% 0,36%Flow (minicone) 43 cm 44,5 cm 42,5 cm 39 cm 40,5 cmCohesivity ***** ***** ***** ***** *****Bleeding *** *** *** *** ***Segregation *** *** *** *** ***Overall filling very bad bad ok good excellent
0,0 0,1 0,2 0,3 0,40,47
0,48
0,49
0,50
0,51
0,52
0,53
0,54
max w/c
max
w/c
% LSds
0,0 0,1 0,2 0,3 0,43
4
5
6
7
8
9
10
11
12
min vis. gamma crit
vis
cosity
(Pas), c
ritical
γ (P
a)
0,0 0,1 0,2 0,3 0,41,0
1,5
2,0
2,5
3,0
shear thinn 0,1/1 shaat thinn 1/gamma cr.
shear
thin
nin
g
% LSds
0,0 0,1 0,2 0,3 0,4
0,6
0,7
0,8
0,9
% LSds
% LSds
shaer thick.
shea
r th
icke
nin
g
Superplasticizer formulations: mortar rheology
parameter Mortar 1b Mortar 4b
w/c 0,50 0,525
PCE (dry solids) 0,24% 0,24%
LS (dry solids) 0,00% 0,27%
Flow 10 min 10 min 40 cm 35 cmCohesivity 10 min ***** *****Bleeding 10 min *** ***Segregation 10 min *** ***
Flow 60 min 60 min
38 cm 41 cm
Cohesivity 60 min ***** *****Bleeding 60 min *** ***Segregation 60 min *** ***
Superplasticizer formulations: workability vs. time
parameter Mortar 1 Mortar 2 Mortar 3 Mortar 4 Mortar 5
w/c 0,475 0,50 0,50 0,50 0,53PCE (dry solids) 0,24% 0,24% 0,24% 0,24% 0,24%LS (dry solids) 0,00% 0,09% 0,18% 0,27% 0,36%Flow (minicone) 43 cm 44,5 cm 42,5 cm 39 cm 40,5 cmCohesivity ***** ***** ***** ***** *****Bleeding *** *** *** *** ***Segregation *** *** *** *** ***Overall filling very bad bad ok good excellent
0 12 24 36 48 60 720
1
2
3
q (m
W/g
sam
ple)
t (h)
Mortar No.1 Mortar No.2 Mortar No.3 Mortar No.4 Mortar No.5
0 12 24 36 48 60 720
5
10
15
20
25
30
Mortar No.1 Mortar No.2 Mortar No.3 Mortar No.4 Mortar No.5
Q (m
Wh/g
sam
ple)
t (h)
0 20 40 60 80 100 120 140
-1
0
1
2
3
4
5
6
7
8
9
q (m
W/g
cem
ent)
t (min)
Paste 1 Paste 2 Paste 3 Paste 4 Paste 5
0 2 4 6 8 10 12 14 16 18 20
-1
0
1
2
3
4
5
6
7
8
9
Paste 1 Paste 2 Paste 3 Paste 4 Paste 5
q
(mW
/gce
ment)
t (min)
Superplasticizer formulations: hydration reaction
parameter Mortar 1 Mortar 2 Mortar 3 Mortar 4 Mortar 5
PCE (dry solids) 0,24% 0,24% 0,24% 0,24% 0,24%LS (dry solids) 0,00% 0,09% 0,18% 0,27% 0,36%
020406080
100% (dry solids)/powder mat.
low consistency loss
robustness
min. powder content/m3
water reductioncohesivity
dynamic segr. Resitence
low concr. viscosity
static segreg. resistence
Superplasticizer formulations: overall aspect on concrete rheology
Valid
for flo
wa b
le con
crte ( SC
C)
Not prooved experimentaly
parameter Mortar 1 Mortar 2 Mortar 3 Mortar 4 Mortar 5
PCE (dry solids) 0,24% 0,24% 0,24% 0,24% 0,24%LS (dry solids) 0,00% 0,09% 0,18% 0,27% 0,36%
Superplasticizer formulations: overall aspect on concrete rheology
0,40 0,35 0,30 0,25
PCE 3
PCE 2
water/powder
pote
ntial
pro
ble
ms
with c
oncre
te rheo
logy
Flowable concrete, SCC, HPCC30/37 S4C25/30 S3
PCE 1
Our pre sentatio n at S
c hleibin ger 201 4