08-Self Consolidating Concrete
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Transcript of 08-Self Consolidating Concrete
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SELF CONSOLIDATING CONCRETE
Effect of Mix Design on Design and
Performance of Precast/Prestressed Girders
Rigoberto Burgueo, Ph.D.Assistant Professor of Structural Engineering
Department of Civil and Environmental Engineering
Michigan State University
BACKGROUND & MOTIVATION
Self-Consolidating Concrete (SCC): a specially proportioned
concrete that can flow easily into forms and around steel
reinforcement without segregation.
The benefits of SCC in reduced labor needs, increased rate of
production and safety, and lower noise levels have generated
great interest from the precast concrete industry.
Considerable development in SCC technology has been made
through the past decades particularly in Japan, Canada, and
Europe, and its applications have become wide spread.
SCC FRESH PROPERTY BEHAVIOR
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BACKGROUND & MOTIVATION
Self-Consolidating Concrete (SCC): a specially proportioned
concrete that can flow easily into forms and around steel
reinforcement without segregation.
The benefits of SCC in reduced labor needs, increased rate of
production and safety, and lower noise levels have generated
great interest from the precast concrete industry.
Considerable development in SCC technology has been made
through the past decades particularly in Japan, Canada, and
Europe, and its applications have become wide spread.
SCC BENEFITS
BACKGROUND & MOTIVATION
Use of SCC in the US has been limited because of concerns
about design and construction issues that are perceived to
influence the structural integrity.
In spite of the rapid developments in SCC technology, most of
the work has focused on mix design development, rheology
characterization, mechanical properties, and in-situ verification.
Very limited information exists on issues related to structural
design and performance.
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A. Increase paste deformability
* use of HRWR
* balanced w/c ratio
B. Reduce inter-particle friction
* low coarse aggregate volume
* use cont. graded powder
Fluidity/Deformability
A. Increase paste deformability
* use of HRWR
* balanced w/c ratio
B. Reduce inter-particle friction
* low coarse aggregate volume
* use cont. graded powder
Fluidity/Deformability
A. Reduce solids separation
* limit aggregate content
* reduce max. size aggregate
* increase cohesion & viscosity
- low w/c ratio
- use of VMA
B. Minimize bleeding
* low w/c ratio
* use of high-area powder
* increase VMA
Homogeneity/Stability
A. Reduce solids separation
* limit aggregate content
* reduce max. size aggregate
* increase cohesion & viscosity
- low w/c ratio
- use of VMA
B. Minimize bleeding
* low w/c ratio
* use of high-area powder
* increase VMA
Homogeneity/Stability
A. Enhance cohesiveness
* low w/c ratio
* use of VMA
B. Compatible flow space and
aggregate size
* low coarse aggregate volume
* low max. size aggregate
Easy Flow/Low Blockage
A. Enhance cohesiveness
* low w/c ratio
* use of VMA
B. Compatible flow space and
aggregate size
* low coarse aggregate volume
* low max. size aggregate
Easy Flow/Low Blockage
Viscosity
Deformability
High Viscosity,LowFluidity
LowViscosity,High Fluidity
Fluidity/Stability
Trade-off
Viscosity
Deformability
High Viscosity,LowFluidity
LowViscosity,High Fluidity
Fluidity/Stability
Trade-off
SCC PROPORTIONING & BEHAVIOR
SCC MIX DESIGN DEVELOPMENT
No commonly accepted procedure to proportion SCC.
Methods are bounded by two approaches:
1) High w/c ratios (e.g., 0.45) and use of HRWR and VMA.
2) Lower w/c ratios (e.g. 0.33), high use of HRWR and no VMA
Approach:Develop characteristic bounding SCC mix designs.
Mix Design w/c HRWR VMA CAC S/Pt EA
SCC-1 0.35 + less more +
SCC-2 0.40 + +/ +
SCC-3 0.45 + + +
NCC 0.40 + more less +
PCI Daniel P. Jenny Research Fellowship on Structural
Performance of PC/PS Girder Bridges using SCC
Objective:
To investigate the transfer and flexural bond length
performance of prestressing strands in pc/ps bridge girders
built using SCC to provide guidance on the construction and
design of these elements with SCC.
MSU SCC RESEARCH Part 1
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MIX DESIGNS PCI Project
Constituents (lbs)
666.6906.14DELVO StabilizerSet Retardant
0913.940Rheomac VMA 358VMA
2878.496.29Glenium 3200 HESHRWR
19.080.50.210.5MB-AETM 90Air Entraining
Admixtures (oz/cwt)
0.40.450.40.40.35w/c Ratio
6%6%6%6%6%(design)Air
280315280280245Water
158014351380138013806 AAGravel
121612751426142615192 NSSand
700700700700700Type-IIICement
NCCBSCC3SCC2BSCC2ASCC1Type
Inverted Slump Flow and VSI Test
127"SCC3
0*24.5"SCC2b
0.525"SCC2a
027"SCC1
Visual
Stability
Index
Slump
Spread
Flow
* Concrete had very low flowability
FRESH PROPERTIES PCI Project
FRESH PROPERTIES PCI Project
41.28SCC3
naSCC2b
23.81SCC2a
1.59SCC1
J-Ring
Value
J-Ring Test
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2, 9*0.69*SCC3
na0.76SCC2b
1, 20.86SCC2a
1, 20.80SCC1
t1, t2
(sec.)
Blocking
Ratio
* Test was done too late
FRESH PROPERTIES PCI Project
L-Box Test
CONSTITUTIVE PROPERTIES fc
Age Of Concrete (days)0 20 40 60 80 100 120 140
CompressiveStrength(psi)
4500
5000
5500
6000
6500
7000
7500
8000
8500
9000
9500
10000
CompressiveStrength(MPa)
30
33
36
39
42
45
48
51
54
57
60
63
66
NCCB
SCC1
SCC2A
SCC2B
SCC3
CONSTITUTIVE PROPERTIES fct
Age Of Concrete (days)
0 20 40 60 80 100 120 140
SplitTensileStr
ength(psi)
400
450
500
550
600
650
700
SplitTensileStrength(MPa)
3.00
3.25
3.50
3.75
4.00
4.25
4.50
4.75
NCCB
SCC1
SCC2A
SCC2B
SCC3
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CONSTITUTIVE PROPERTIES Ec
Concrete Age (days)
0 5 10 15 20 25 30
ElasticModulus(psi)
2.6e+6
2.8e+6
3.0e+6
3.2e+6
3.4e+6
3.6e+6
3.8e+6
4.0e+6
4.2e+6
4.4e+6
4.6e+6
ElasticModulus(GPa)
18
20
22
24
26
28
30
SCC1
SCC2a
SCC2b
SCC3
NCCb
TRANSFER AND DEVELOPMENT
LENGTH OF PRESTRESSING STRANDS
2 beams per concrete mix 4 flexural bond tests per mix.
2 1/2-in. diameter strands - Stressed at ~ 0.75fu
38 ft in length.
CrossSection:
3 SCC mix designs that bound mix currentdesign approaches
1 normally consolidated concrete (NCC)mix as a control mix
SCC mix performance was to be evaluated
PRODUCTION PLAN
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Casting Bed and Stressing Operation
Casting Operation with SCC Mix
Formwork Removal and Instrumentation
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Prestress Release Operation
TRANSFER LENGTH EVALUATION
Strand Pull-In Concrete Strain Profile
MIX TYPE
NCCB SCC1 SCC2A SCC2B SCC3
StrandDraw-
in(in.)
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
StrandDraw-in(mm)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Strand Draw-in Measurements
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Average Strain Profile for SCC1 Beams
Distance Along Beam (in.)
0 10 20 30 40 50 60 70 80 90 100
ConcreteStrain
0
1e-4
2e-4
3e-4
4e-4
5e-4
Distance Along Beam (mm)
0 250 500 750 1000 1250 1500 1750 2000 2250 2500
Lt= 719 mm
(28.3 in.)
95% AMS
SCC1
Transfer Length Evaluation PCI Phase 1
MIX TYPENCCB SCC1 SCC2A SCC2B SCC3
Transferlength(in.)
0
5
10
15
20
25
30
35
40
45
Transferlength(mm)
0
100
200
300
400
500
600
700
800
900
1000
1100 Concrete Strains
Strand Draw-in
ACI / AASHTO
Transfer Length Evaluation PCI Phase 2
MIX TYPE
NCC SCC1 SCC2 SCC3
Transferleng
th(in.)
0
5
10
15
20
25
30
35
40
45
Transferlengt
h(mm)
0
100
200
300
400
500
600
700
800
900
1000
1100 Concrete Strains
Strand Draw-in
ACI / AASHTO
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Transfer Length Evaluation Summary
MIX TYPE
NCC SCC1 SCC2 SCC3
Transferlength(in.)
0
5
10
15
20
25
30
35
40
45
Transferlength(mm)
0
100
200
300
400
500
600
700
800
900
1000
1100 Phase1
Phase2
Average ACI Lt = 760.98 mm (29.96 in.)
MIX TYPE
NCC SCC1 SCC2 SCC3
Transferlength(in.)
0
5
10
15
20
25
30
35
40
45
Transferlength(mm)
0
100
200
300
400
500
600
700
800
900
1000
1100 Phase1
Phase2
Average ACI Lt = 760.98 mm (29.96 in.)
DEVELOPMENT LENGTH EVALUATION
Development Length Test Setup
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Failure Modes
Flexure Failure Bond-Slip/Shear Failure
Typical Response with Flexure/Bond Failure
Displacement at the section (in.)0 1 2 3 4 5 6 7 8 9 10 11
Moment(kip-ft)
0
10
20
30
40
50
60
70
80
90
Displacement at the section (mm)
0 25 50 75 100 125 150 175 200 225 250 275
Moment(KN-m)
0
10
20
30
40
50
60
70
80
90
100
110
120
SCC3-2BLda = 103.0 in.
Mn = 116.87 kN-m (86.20 k-ft)
Slip Onset
Slip @ Mn = 3.500 mm (0.137 in.)
Displacement at the section (in.)0 1 2 3 4 5 6 7 8 9 10 11
Moment(kip-ft)
0
10
20
30
40
50
60
70
80
90
Displacement at the section (mm)
0 25 50 75 100 125 150 175 200 225 250 275
Moment(KN-m)
0
10
20
30
40
50
60
70
80
90
100
110
120
SCC3-2BLda = 103.0 in.
Mn = 116.87 kN-m (86.20 k-ft)
Slip Onset
Slip @ Mn = 3.500 mm (0.137 in.)
Development Length Test Results Phase 1
ACI - 318
test
n A CI
M
M
d test
d A CI
L
L
.d expt
d A CI
L
L
SCC1 1.06 1.07 1.03SCC2A 1.11 1.09 1.04SCC2B 1.01 1.21 1.17SCC3 1.09 1.79 1.42NCCB 1.04 1.06 0.97
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Development Length Test Results Phase 2
ACI - 318
test
n A CI
M
M
d test
d A CI
L
L
.d expt
d A CI
L
L
SCC1 1.06 1.10 1.05SCC2 1.02 1.04 1.03SCC3 1.05 0.93 0.84NCC 1.11 1.06 0.96
CONCLUSIONS Part 1: PCI Project
The presented studies are serving as an evaluation of SCC mix
designs on the structural performance of precast SCC elements.
SCC mix designs with moderate w/c ratios and moderate use of
HRWR and VMA behave closer to NCC mixes without any
chemical admixtures.
Transfer lengths determined by draw-in and concrete strain
measurements indicate that the ACI equation applies to SCC.
Results from flexural tests indicate that development lengths for
SCC mixes were s lightly longer than code predicted values.
CONCLUSIONS Part 1: PCI Project
The much longer development lengths found for SCC during the
PCI Phase-1 project were verified to be due to poor strand quality.
Development length tests using a pre-qualified strand, known to
have very good properties, indicated that SCC mix designs doaffect the flexural bond mechanism of prestressing strands but in
a slight manner. A more definite position by the research team is
under consideration.
SCC mix proportioning seems to have different effects on the
associated bond mechanisms controlling transfer and flexural
bond length.
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MDOT/FHWA IBRC Project: Experimental Evaluation and
Field-Monitoring of Bridge Precast/Prestressed Box-Girders
made from Self-Compacting-Concrete
Objective:
To implement SCC in the precast/prestressed box beams of a
demonstration bridge and to evaluate their short- and long-
term performance against the behavior of beams from
normally consolidated concrete.
MSU SCC RESEARCH Part 2
Bridge Deck
Beam 1
Beam 2
Beam 3
Beam 4
Beam 5
Beam 6
5 @ 8'-8"49'
52'Elevation View
Plan View
M-50/US-127 Bridge Over the Grand River
Consider 3 SCC mix designs that bound current designapproaches.
Consider 1 normally consolidated concrete (NCC) mix as a
control mix.
The short-term flexure and shear performance of the SCCbeams should be verified to be equal or better than that ofthe NCC beams through full-scale testing.
The long-term performance of the SCC beams incomparison to the NCC beams to be continuouslymonitored for a year (or more?).
APPROACH
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3 NCC and 3 SCC (one for each mix design) beams for
demonstration bridge
2 NCC and 6 SCC (two of each mix design) for
experimental evaluation
3 reserve NCC beams for bridge placement in case of
unsatisfactory SCC performance
Total: 17 Beams, 8 NCC and 9 SCC
BEAM PRODUCTION
44.447.752.954.1S/A Ratio (%)
Constituents (lbs)
0621Rheomac
VMAVMA
810.71215Glenium 3400HRWR
1111MBAE90Air Entraining
Admixtures (oz/cwt)
0.400.460.410.37w/c Ratio
6%6%6%6%(design)Air
280320285256Water
1,6001,4501,3501,3506 AAGravel
1,2771,3201,5131,5912 NSSand
700700700700Type-IIICement
NCCSCC3SCC2SCC1Type
MIX DESIGNS IBRC Project
Strand Bond Evaluation Mock-up Production
Fresh Property
Evaluation
MIX DESIGN EVALUATION
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27"
36"
16 Prestressing Strands
0.6" diameter
5 #4 Bars
spaced at 6"
4.5"
4.5"
5"
BEAM CROSS SECTION
NCC Beam Production
Cast in two operations
Increased laborand time
BEAM PRODUCTION
SCC Beam Production
Cast in one operation
Reduced labor andtime
EXPERIMENTAL EVALUATION
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Experimental evaluation was conducted atMSUs Civil Infrastructure Laboratory
Two test beams were cast for each concrete
One was to be evaluated for flexural response
Four total tests
One was to be evaluated for shear response
Four total tests
EXPERIMENTAL APPROACH
FLEXURAL EVALUATION
Test Beam
Actuator
Reaction Floor Support Block
8
50
52
21
Reaction Frame
FLEXURAL TEST SETUP
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FLEXURAL FAILURE MODE
Displacement (in.)
0 1 2 3 4 5 6 7 8 9 10
Load(kip)
0
10
20
30
40
50
60
70
80
Design-Full*
Design-Reduced*
*Nominal-AASHTO 17th Ed.
NCCSCC 1SCC 2
SCC 3
P P
P P
FLEXURE TEST RESULTS
Curvature (1/in.)
0.0000 0.0001 0.0002 0.0003 0.0004
Moment(kip-ft)
0
200
400
600
800
1000
1200
1400
1600
1800
Design-Full*Design-Reduced*
*Nominal-AASHTO 17th
Ed.
NCC
SCC 1
SCC 2
SCC 3
P P
M
P P
M
FLEXURE TEST RESULTS
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ACHIEVED FLEXURAL CAPACITIES
Maximum Total
Moment
(kip-ft)
Design Moment
[AASHTO]
(kip-ft)
Actual to Design
Ratio
NCC 1,649 1,499 1.10
SCC1 1,628 1,499 1.09
SCC2 1,593 1,499 1.06
SCC3 1,590 1,499 1.06
* According to AASHTO Standard Specifications 17th Ed.
*
SHEAR EVALUATION
SHEAR TEST SETUP
Reaction Frame
Actuator
Shear Deformation PanelTest
Beam
Support Block Reaction Floor
Lv22-Lv 852
NCC: Lv = 11 ftSCC: Lv = 9 ft
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SHEAR FAILURE MODE
Displacement (in.)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
Load(kip)
0
20
40
60
80
100
120
140
160
180
200For all SCC Beams: Lv= 9 ft
For NCC Beam: Lv= 11 ft
AASHTO LRFD 2nd Ed.Design Nominal Capacity[L
v=9 ft]
AASHTO LRFD 2nd
Ed.Design Nominal Capacity[Lv=11 ft]
Note: AASHTO 17th Ed.:176 kipDesign Nominal Capacity
NCC
SCC 1
SCC 2
SCC 3
LvP P
Shear SectionLv
P P
Shear Section
SHEAR TEST RESULTS
Curvature (1/in.)
0.00000 0.00005 0.00010 0.00015 0.00020
Moment(kip-ft)
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
AASHTO LRFD 2nd Ed.Design Nominal Capacity[Lv=11 ft]
AASHTO LRFD 2nd Ed.Design Nominal Capacity[Lv=9 ft]
Note: Design Nominal Capacity: 1546 kip-ft
[AASTHO 17th Ed.]
For all SCC Beams: Lv=9 ft
For NCC Beam: Lv=11 ft
NCC
SCC 1
SCC 2
SCC 3
LvP P
Shear Section
.89 MM
SHEAR TEST RESULTS
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Average Shear Strain (microstrain)
0 250 500 750 1000 1250 1500 1750 2000
ShearForce(kips)
0
20
40
60
80
100
120
140
160
180
SCC1 Exp_avg
NCC Exp_avg
SCC2 Exp_avg
NCC - AASHTO-LRFD 2nd
Ed.[f'c=5500psi, Lv=11ft]
SCC3 Exp_avg
SCC - AASHTO-LRFD 2nd
Ed.[f'c=5500psi, Lv=9ft]
LvP P
Shear SectionLv
P P
Shear SectionLv
P P
Shear SectionLv
P P
Shear Section
SHEAR TEST RESULTS
ACHIEVED SHEAR CAPACITIES
Maximum Total
Shear
(kip)
Design Shear
[AASHTO]
(kip)
Actual to Design
Ratio
NCC 128 116 1.11
SCC1 159 130 1.22
SCC2 146 130 1.12
SCC3 140 130 1.08
* According to AASHTO-LRFD Simplified Section Analysis Method
*
Beams placed: 9/15/05Open to traffic: Late October
BRIDGE CONSTRUCTION
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SCC 3 - Instrumented
SCC 2 - Instrumented
SCC 1 - Instrumented
NCC - Instrumented
NCC
NCCInstruments per Girder:
8 Vibrating Wire Strain
Gages 8 Thermocouples
FIELD MONITORING
System deployed: 12/20/05
All beams exceeded design capacities and were implementedin the demonstration bridge.
The capacities of the NCC beams were slightly higher thenthose of the SCC beams.
The different SCC mix designs were seen to have an effect onflexural displacements as well as in the shear post-crackingbehavior.
The field-monitoring program is underway and an automateddata reduction program with potential web broadcast is under
development.
CONCLUSIONS Part 2: IBRC Project
ACKNOWLEDGEMENTS
The authors are grateful for the financial and in-kind support
provided by:
PCIthrough a 2003-2004 D.P. Jenny Research Fellowship.
MDOT and FHWA through a 2005 IBRC Project.
The Premarc Corp. in-kind labor and materials
Degussa Admixtures Inc. technical support and materials
The CEE Department at Michigan State University
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ACKNOWLEDGEMENTS
The authors also gratefully acknowledge the collaborating effort and
many fruitful discussions with:
Mr. Armand Atienza (Formerly with Degussa)
Mr. Doug Burnett (Formerly with Degussa)
Mr. Tom Grumbine (Premarc)
Mr. Don Logan (Stresscon)
Mr. Horacio Lopez (Premarc)
Dr. Charles Nmai (Degussa)
Mr. Fernando Roldan (Premarc)
Mr. Roger Till (MDOT)
Mr. Chad Woodward (Degussa)
ACKNOWLEDGEMENTS
The experimental work for the presented projects was conducted at
MSUs Civil Infrastructure Laboratory. The work could not have
been possible with the aide and assistance of its staff and student
researchers, including:
Mr. David Bendert
Mr. James Brenton
Mr. Steven Franckowiak
Mr. Mahmoodul Haq
Mr. Siavosh Ravanbakhsh