8-self consolidating concrete - michigan local technical...

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SELF CONSOLIDATING CONCRETE

Effect of Mix Design on Design and Performance of Precast/Prestressed Girders

Rigoberto Burgueño, Ph.D.Assistant Professor of Structural Engineering

Department of Civil and Environmental EngineeringMichigan 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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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


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, rheologycharacterization, 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 andaggregate size* low coarse aggregate volume* low max. size aggregate

Easy Flow/Low BlockageA. Enhance cohesiveness

* low w/c ratio* use of VMA

B. Compatible flow space andaggregate size* low coarse aggregate volume* low max. size aggregate

Easy Flow/Low Blockage

Viscosity

Def

orm

abili

ty

High Viscosity,Low Fluidity

Low Viscosity,High Fluidity

Fluidity/StabilityTrade-off

Viscosity

Def

orm

abili

ty

High Viscosity,Low Fluidity

Low Viscosity,High Fluidity

Fluidity/StabilityTrade-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 Retardant0913.940Rheomac® VMA 358 VMA2878.496.29Glenium® 3200 HESHRWR19.080.50.210.5MB-AETM 90Air Entraining

Admixtures (oz/cwt)0.40.450.40.40.35w/c Ratio6%6%6%6%6%(design)Air280315280280245Water158014351380138013806 AAGravel121612751426142615192 NSSand700700700700700Type-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


41.28SCC3

naSCC2b

23.81SCC2a

1.59SCC1

J-RingValue

J-Ring Test

5

2, 9*0.69*SCC3

na0.76SCC2b

1, 20.86SCC2a

1, 20.80SCC1

t1, t2(sec.)

BlockingRatio

* Test was done too late


L-Box Test

CONSTITUTIVE PROPERTIES – f’c

Age Of Concrete (days)0 20 40 60 80 100 120 140

Com

pres

sive

Str

engt

h (p

si)

4500

5000

5500

6000

6500

7000

7500

8000

8500

9000

9500

10000

Com

pres

sive

Str

engt

h (M

Pa)

30333639424548515457606366

NCCBSCC1SCC2ASCC2BSCC3

CONSTITUTIVE PROPERTIES – fct

Age Of Concrete (days)0 20 40 60 80 100 120 140

Split

Ten

sile

Str

engt

h (p

si)

400

450

500

550

600

650

700

Split

Ten

sile

Str

engt

h (M

Pa)

3.00

3.25

3.50

3.75

4.00

4.25

4.50

4.75

NCCBSCC1SCC2ASCC2BSCC3

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CONSTITUTIVE PROPERTIES – Ec

Concrete Age (days)

0 5 10 15 20 25 30

Elas

tic M

odul

us (p

si)

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

Elas

tic M

odul

us (G

Pa)

18

20

22

24

26

28

30

SCC1SCC2aSCC2b SCC3NCCb

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 current design 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

Stra

nd D

raw

- in

(in.

)

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

Stra

nd D

raw

- 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 BeamsDistance Along Beam (in.)

0 10 20 30 40 50 60 70 80 90 100

Con

cret

e St

rain

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

Tran

sfer

leng

th (i

n.)

0

5

10

15

20

25

30

35

40

45

Tran

sfer

leng

th (m

m)

0

100

200

300

400

500

600

700

800

900

1000

1100 Concrete StrainsStrand Draw-inACI / AASHTO

Transfer Length Evaluation – PCI Phase 2

MIX TYPENCC SCC1 SCC2 SCC3

Tran

sfer

leng

th (i

n.)

0

5

10

15

20

25

30

35

40

45

Tran

sfer

leng

th (m

m)

0

100

200

300

400

500

600

700

800

900

1000

1100 Concrete StrainsStrand Draw-inACI / AASHTO

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Transfer Length Evaluation – Summary


Tran

sfer

leng

th (i

n.)

0

5

10

15

20

25

30

35

40

45

Tran

sfer

leng

th (m

m)

0

100

200

300

400

500

600

700

800

900

1000

1100 Phase1Phase2

Average ACI Lt = 760.98 mm (29.96 in.)


Tran

sfer

leng

th (i

n.)

0

5

10

15

20

25

30

35

40

45

Tran

sfer

leng

th (m

m)

0

100

200

300

400

500

600

700

800

900

1000

1100 Phase1Phase2

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 FailureDisplacement at the section (in.)

0 1 2 3 4 5 6 7 8 9 10 11

Mom

ent (

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

Mom

ent (

KN

-m)

0102030405060708090

100110120

SCC3-2BLda = 103.0 in.

Mn = 116.87 kN-m (86.20 k-ft)

Slip OnsetSlip @ Mn = 3.500 mm (0.137 in.)

Displacement at the section (in.)0 1 2 3 4 5 6 7 8 9 10 11

Mom

ent (

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

Mom

ent (

KN

-m)

0102030405060708090

100110120

SCC3-2BLda = 103.0 in.

Mn = 116.87 kN-m (86.20 k-ft)

Slip OnsetSlip @ Mn = 3.500 mm (0.137 in.)

Development Length Test Results – Phase 1

ACI - 318

test

n ACI

MM −

d test

d ACI

LL

−

−

.d expt

d ACI

LL

−

−

SCC1 1.06 1.07 1.03 SCC2A 1.11 1.09 1.04 SCC2B 1.01 1.21 1.17 SCC3 1.09 1.79 1.42 NCCB 1.04 1.06 0.97

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Development Length Test Results – Phase 2

ACI - 318

test

n ACI

MM −

d test

d ACI

LL

−

−

.d expt

d ACI

LL

−

−

SCC1 1.06 1.10 1.05 SCC2 1.02 1.04 1.03 SCC3 1.05 0.93 0.84 NCC 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 slightly 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 do affect 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 design approaches.

Consider 1 normally consolidated concrete (NCC) mix as a control mix.

The short-term flexure and shear performance of the SCC beams should be verified to be equal or better than that of the NCC beams through full-scale testing.

The long-term performance of the SCC beams in comparison to the NCC beams to be continuously monitored 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® VMAVMA810.71215Glenium® 3400HRWR1111MBAE90Air Entraining

Admixtures (oz/cwt)

0.400.460.410.37w/c Ratio6%6%6%6%(design)Air280320285256Water

1,6001,4501,3501,3506 AAGravel1,2771,3201,5131,5912 NSSand700700700700Type-IIICement

NCCSCC3SCC2SCC1Type

MIX DESIGNS – IBRC Project

Strand Bond Evaluation Mock-up Production

Fresh Property Evaluation

MIX DESIGN EVALUATION

15

27"

36"

16 Prestressing Strands 0.6" diameter

5 #4 Bars spaced at 6"

4.5"

4.5"

5"

BEAM CROSS SECTION

NCC Beam ProductionCast in two operations

Increased labor and time

BEAM PRODUCTION

SCC Beam ProductionCast in one operation

Reduced labor and time

EXPERIMENTAL EVALUATION

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• Experimental evaluation was conducted at MSU’s 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.

NCC SCC 1 SCC 2 SCC 3

P P

δ

P P

δ

FLEXURE TEST RESULTS

Curvature (1/in.)

0.0000 0.0001 0.0002 0.0003 0.0004

Mom

ent (

kip-

ft)

0

200

400

600

800

1000

1200

1400

1600

1800

Design-Full*Design-Reduced*

*Nominal-AASHTO 17th

Ed.

NCCSCC 1SCC 2SCC 3

P P

M

δ

P P

M

δ

FLEXURE TEST RESULTS

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ACHIEVED FLEXURAL CAPACITIES

Maximum Total Moment

(kip-ft)

Design Moment [AASHTO]

(kip-ft)

Actual to DesignRatio

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 8’52’

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 ftFor NCC Beam: Lv= 11 ft

AASHTO LRFD 2nd Ed.Design Nominal Capacity[Lv=9 ft]


Note: AASHTO 17th Ed.:176 kipDesign Nominal Capacity

NCCSCC 1SCC 2SCC 3

Lv

P P

Shear SectionLv

P P

Shear Section

SHEAR TEST RESULTS

Curvature (1/in.)

0.00000 0.00005 0.00010 0.00015 0.00020

Mom

ent (

kip-

ft)

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300



Note: Design Nominal Capacity: 1546 kip-ft [AASTHO 17th Ed.]

For all SCC Beams: Lv=9 ftFor NCC Beam: Lv=11 ft

NCCSCC 1SCC 2SCC 3

Lv

P 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

Shea

r For

ce (k

ips)

0

20

40

60

80

100

120

140

160

180

SCC1 Exp_avgNCC 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]

Lv

P 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 DesignRatio

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



NCC - Instrumented

NCC

NCC Instruments per Girder:

8 Vibrating Wire Strain Gages

8 Thermocouples

FIELD MONITORING

System deployed: 12/20/05

All beams exceeded design capacities and were implemented in the demonstration bridge.

The capacities of the NCC beams were slightly higher then those of the SCC beams.

The different SCC mix designs were seen to have an effect on flexural displacements as well as in the shear post-cracking behavior.

The field-monitoring program is underway and an automated data 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:

PCI through a 2003-2004 D.P. Jenny Research Fellowship.MDOT and FHWA through a 2005 IBRC Project.The Premarc Corp. – in-kind labor and materialsDegussa Admixtures Inc. – technical support and materialsThe 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 MSU’s Civil Infrastructure Laboratory. The work could not have been possible with the aide and assistance of it’s staff and student researchers, including:

Mr. David Bendert Mr. James BrentonMr. Steven FranckowiakMr. Mahmoodul HaqMr. Siavosh Ravanbakhsh

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