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ACI Spring Convention – Minneapolis April 14, 2013 1
Use of Fiber-Reinforced SCC for the Repair of Reinforced Concrete Beams
Kamal Khayat, Missouri University of Science & Technology
Fodhil Kassimi, Université de Sherbrooke, Canada
ACI Spring Convention
Minneapolis - April 15, 2013
Building construction
Precast architectural
applications
Hydro-electric facilities
Mass foundations
Building construction
Transportation structures
NSERC High-Performance Flowable Concrete
with Adapted Rheology
Infrastructure
rehabilitation
Flowable mass
concrete
Semi-flowable
SCC
SCC FR-SCC
MO-S MU-S ST
Fiber type and characteristics
ST-PP
Synthetic
92% steel +
8% polypropylene
Hybrid Metallic
Lf (mm) 40 50 5-15 and 42 30
Lf / df 90 74 47 55
Ef (GPa) 9.5 5 203 (steel portion) 200
Monofilament Multifilament Hooked ends
Objectives
Compare performance of
various types of FR-SCC
Compare performance of SCC,
FR-SCC, and CVC
Experimental program
Parameters
Repair material
Concrete (SCC) vs. mortar (CEM)
Reinforcement
Fiber type (steel, synthetic, and hybrid)
Fiber volume
0.3% and 0.5% for FR-SCC
1.4% for CEM
3 rebars in repair zone for SCC vs. 2 rebars for FR-SCC
Typical mixture proportioning
Ref. SCC ST 0.5%
w/cm 0.42 0.42
Binder (GUb-S/FS) (kg/m3) 475 475
Paste volume (binder + water + air)
(L/m3)
415 415
Crushed coarse aggregate, 5-10 mm
(L/m3)
290 273
Sand-to-aggregate ratio (by volume) 1.00 1.07
Air content (%) 5.9 7.0
Slump flow (mm) 720 705
Workability
characteristics & test
methodsDeformability
Passing ability
Filling capacity
Stability
Rheology
Consolidation protocol
of SF-FR-SCC and
risk of segregation
Hardened propertiesCompressive strength
Splitting tensile strength
Avg. residual strength
Drying shrinkage
Restrained shrinkage
Flexural creep
Testing and performance of FR-SCC
Workability assessment
Slump flow vs. fiber factor
R2= 0.88
R2= 0.92
400
500
600
700
800
0 10 20 30 40 50 60 70
Vf L f / d f
Slump-flow (mm)
MO-S MU-S MI-MA ST-PP ST
Synthetic fibers
Metallic &
hybrid fibers
Modified J-Ring setup for FR-SCC and FR-CEM
ASTM C 1621 Modified
Clear spacing 43 ± 1.5 mm 2.5 × Lf � 125 ± 15 mm
No. of bars 16 8
ASTM C 1621 J-Ring test setup Modified J-Ring with 8 bars
Modified J-Ring spread vs. fiber factor
R2 = 0.86
R2 = 0.91
350
450
550
650
750
0 10 20 30 40 50 60 70
Vf Lf / df
J-Ring spread (mm)
MO-S MI-S MI-MA ST-PP ST
Synthetic fibers
Metallic &
hybrid fibers
Clear spacing 2.5 × Lf � 125 ± 15 mm
No. of bars 8
D
a
R2 = 0.80
0
5
10
15
20
25
0 10 20 30 40 50 60 70
Vf Lf / df
D / a
MO-S MU-S MI-MA ST-PP ST
Clear spacing 2.5 × Lf � 125 ± 15 mm
No. of bars 8
Modified L-box setup for fibrous mixtures (FR-SCC and FR-CEM)
Free spacing between bars = {1 bar for FR-SCC
80 mm ≈ 2.5 × Lf for FR-SCC (modified box)
3 x 12 mm bars for SCC
35 mm for SCC (conventional box)
Blockage of FR-SCC
Surface Settlement
0.0
0.1
0.2
0.3
0.4
0.5
0 2 4 6 8 10 12 14 16 18
Age of concrete (h)
Settlement (%)
ST-PP 0.75%
ST 0.75%
SCC
ST-PP 0.5%MO-S 0.5%
MO-S 0.75%
ST 0.5%
No clear relation of settlement between SF-FR-SCC and FR-SCC
SF-FR-SCC
Workability requirements SF-FR-SCC FR-SCC
Slump flow (mm)
J-Ring (D/a)
V-funnel (sec)
L-box blocking ratio
Filling capacity (%)
Surface settlement (%)
500 – 600
7-12
> 7
0.2 – 0.6
40 – 50
≤ 0.5
600 – 730
12-23
≤ 7
0.6 – 1
50 –100
≤ 0.5
Typ. workability characteristics forSF-FR-SCC and FR-SCC
Compressive strength
35
40
45
50
55
0 10 20 30 40 50 60 70
Vf Lf / df
21d-f' c (MPa)
MO-S MU-S MI-MA ST-PP ST
Slight strength drop with MO-S and ST fibers at 0.75% Vf (lack of consolidation)
Splitting tensile strength
3.5
4.5
5.5
6.5
0 10 20 30 40 50 60 70
Vf Lf / df
21d-f' sp (MPa)
MO-S MU-S MI-MA ST-PP ST
Slight strength drop with MO-S and ST fibers at 0.75% Vf (lack of consolidation)
Initial loading
Re-loading
(MPa)
+++=
2
25.100.175.050.0
.4
)(
db
LPPPPARS
Deflection rate = 0.65 mm/min
Average residual strength (ASTM C 1399-04) (toughness)
Average residual strength
0
1
2
3
4
5
0 10 20 30 40 50 60 70
ARS (MPa)
Vf Lf / df
MO-S MU-S MI-MA ST-PP ST
* Vf = 0.25%, 0.5% and 0.75% for MO-S and ST* Vf = 0.5% and 0.75% for MU-S, MI-MA and ST-PP
Drying shrinkage (Monolifament synthetic fibers)
0
300
600
9000
30
60
90
120
150
180
210
240
270
300
330
360
390
Time of exposure (days)
Drying shrinkage (µm/m)
SCC
MO-S 0.25%
MO-S 0.5%
MO-S 0.75%
Drying shrinkage(Multifilament synthetic fibers)
0
300
600
900
0
30
60
90
120
150
180
210
240
270
300
330
360
390
Time of exposure (days)
Drying shrinkage (µm/m)
SCC
MU-S 0.5%
MU-S 0.75%
Drying shrinkage(80% macro – 20% micro synthetic fibers)
0
300
600
9000
30
60
90
120
150
180
210
240
270
300
330
360
390
Time of exposure (days)
Drying shrinkage (µm/m)
SCC
MI-MA 0.5%
MI-MA 0.75%
Drying shrinkage(92% steel – 8% polypropylene fibers)
0
300
600
900
0
30
60
90
120
150
180
210
240
270
300
330
360
390
Time of exposure (days)
Drying shrinkage (µm/m)
SCC
ST-PP 0.5%
ST-PP 0.75%
Greater area refers to
better performanceHRWRA
21d-ARS
21d-f’sp
Slump flow
Filling capacity
Shrinkage
Overall performance evaluation using “close-loop’’ plot
Overall performance
SF-FR-SCC has lower performance than SCC and FR-SCC
MO-S MU-S
ST
ST-PP
Monofilament Multifilament
Workability
characteristics & test
methodsDeformability
Passing ability
Filling capacity
Stability
Rheology
Consolidation of SF-
FR-SCC
Hardened propertiesCompressive strength
Splitting tensile strength
Avg. residual strength
Drying shrinkage
Restrained shrinkage
Flexural creep
Structural performanceMonolithic beams
Repaired beams
Testing and performance of FR-SCC
Monolithic
Beams
(2 bars)
Repair beams (2
bars)
(CVC base)
2 CVC (ref.)
SCC SCC
SCC3 (3 bars)
MO-S 0.3%
MO-S 0.5% MO-S 0.5%
ST-PP 0.3%
ST-PP 0.5% ST-PP 0.5%
ST 0.3%
ST 0.5% 2 ST 0.5%
ST 1.4% (CEM)
3100
1050250 500 1050 250
250
400 2 Νο.10Μ
8 mm @ 150 mmNo. 20M varies (2 to 3)φ
Workability characteristics of the investigated beam mixtures
Mixture
Slump-flow
(mm)
J-Ring (m
m)
Air volume
(%)
V-Funnel (s)
L-box h 2/h
1
Filling
capacity (%)
CVC 110 -- 7 -- -- --
SCC 720 715 5.9 2.7 0.99 100
MO-S 0.3% 710 700 8.9 3 1 97
MO-S 0.5% 700 680 9 4.1 0.91 93
ST-PP 0.3% 705 700 6.3 3 0.96 97
ST-PP 0.5% 700 675 6.6 4.8 0.90 90
ST 0.3% 715 708 6.8 3 0.98 97
ST 0.5% 705 687 7 3.6 0.92 95
ST 1.4% 720 716 9 1.8 0.98 96
Effect of concrete type
CC SCC
Effect of fiber
contribution
MO-S 0.5%
MU-S 0.5%
ST-PP 0.5%
ST 0.5%
Effec
t of fiber
type
Effect of fiber
contribution
MU-S 0.5%
ST 0.5%
Effect of
longitudinal bars
type
SCC with FRPEffect of longitudinal
bars type
CC with FRP
Effect of range
of flowability
SF-SCC
ST ≥ 0.75%
SF-SCC
MU-S ≥ 0.75% Effec
t of fiber
type
CC
Rep
rese
ntative
mea
n
Effec
t of fiber
type
FRP: Fiber-reinforced polymer
CVC: Conventional vibrated concrete
SF-SCC: Semi-flowable self-consolidating concrete
Red: already tested
Black: to be tested
Ongoing work (13 monolithic beams)
CEM: Concrete equivalent mortar
Red: already tested
Black: to be tested
SCC
Effect of fiber
contribution
MO-S 0.5%
MU-S 0.5%
ST-PP 0.5%
ST 0.5%
Effec
t of fiber type
Effect of reinforcement
density
SCC with 3
longitudinal barsEffect of mixture
nature
CEM
ST 1.4%
MO-S 0.3%
MU-S 0.3%
ST-PP 0.3%
ST 0.3%
ST 0.5%
Rep
rese
nta-
tivem
ean
Effect of stay-in-
place formwork
performance
SCC
ST 0.5%
Effect of fiber
contribution in
the repair
material
Rep
rese
nta-
tivem
ean
MU-S 0.5%
Effec
t of fiber
type
Effect of fiber
volume
Ongoing work (15 repaired beams)
Repair procedure
Covering reinforcement in repair
zone with duct tapePlacing PVC duct (150 mm) in
inverted reinforcing cage
Sealing placement ducts from both ends
Holes
140 mm diameter
900 100
125
1000 250
400
Normal concrete
100 1000
Repair procedure
Casting of CC
substrate
Repair procedure
Spraying substrate with set
retardant shortly after casting
Water-jetting after 1 day to remove
surface mortar
Interface cleaned and duct tape removedPVC mold removed
Repair procedure
Lifting of inverted and partially cast
beam for intermediary preparations Breaking and removing the PVC molds
Mechanically roughened hole surface to increase bonding quality
Repair procedure
+
Wet curing of substrate concrete (CVC) for 14 days
Return to normal position for repair
Repair procedure
Wet curing of repaired beam for 14 days
Curing of repair beams
Air-curing in laboratory till flexural
testing (6 months)
Workability characteristics
Mixture
Slump-flow
(mm)
J-Ring
(mm)
Air volume
(%)
V-Funnel
(s)
L-box h 2/h
1
Filling
Cap. (%)
CVC 110 -- 7 -- -- --
SCC 720 715 5.9 2.7 0.99 100
MO-S 0.3% 710 700 8.9 3 1 97
MO-S 0.5% 700 680 9 4.1 0.91 93
ST-PP 0.3% 705 700 6.3 3 0.96 97
ST-PP 0.5% 700 675 6.6 4.8 0.90 90
ST 0.3% 715 708 6.8 3 0.98 97
ST 0.5% 705 687 7 3.6 0.92 95
ST 1.4% 720 716 9 1.8 0.98 96
Cores for compression (100×200 mm)
Core through hole filled
with repair concrete (A) P PCore from hole filled with
repair concrete (B)
(D = 95 mm)
Cores for compressive strength
@ A: mean (f’c core / f’c cylinder) = 1
@ B: mean (f’c core / f’c cylinder) = 0.92
0.70
0.80
0.90
1.00
1.10
f'ccore/ f'ccylinder
1.00
0.97 1.01
0.91
1.04
0.95
1.07
1.03
Point A
0.94
0.91
0.89
0.84
0.91
0.93
1.04
0.88
Point B
Loading and strain-control systems
2 strain-gauges for reinforcement
P
2 strain-gauges for concrete
250 250
400
5001050 1050
2 LVDT
P
Load vs. mid-span deflection (repair beams)
0
50
100
150
200
250
300
0 10 20 30 40 50 60 70 80 90
Deflection (mm)
SCC 2bars
SCC 3barsUltimate load
Yield load
Crack load
Load (kN)
Summary of mechanical loads for monolithic beams (2 bars)
0
50
100
150
200
250
300
Load (kN)
45 55 60
Crack load
153
150
192
Yield load
216
219 248
Ultimate load
Load vs. mid-span deflection (ref. beam and repair beams : 2 bars)
0
50
100
150
200
250
300
0 10 20 30 40 50 60 70 80 90
Deflection (mm)
CVC (mono ref.)
MO-S 0.3% MO-S 0.5%
ST-PP 0.3% ST- PP 0.5%
ST 0.3% ST 0.5%
ST 1.4%
Load (kN)
Summary of mechanical loads (ref. beam and repair beams)
0
50
100
150
200
250
300
Load (kN)
45 50
50 56 58
55 57 65
60 62
Crack load
153
148
213
150
151
157
152 169
176
182
Yield load
216 230
267
206
213
204 230
227
224
216
Ultimate load
Repaired / mono CVC beams increase: crack
load: 10% to 40%
yield load: up to 40%
ultimate load: up to 25%
Load vs. crack width
0
50
100
150
200
250
300
0 2 4 6 8 10 12
Load(kN)
Crack width (mm)
CVC (mono)
ST-PP 0.3% ST-PP 0.5%
MO-S 0.3% MO-S 0.5%
ST 0.3% ST 0.5%
ST 1.4% (CEM)
Crack width
Repaired / mono CVC beams decrease: 15% to 60% lower (mean of 40%)
Toughness and stiffness
Increase in repair beam loads compared to CVC
Toughness: -1% to 26% (mean of 13%)
Stiffness : -4% to 21% (mean of 6%)
0
4000
8000
12000
16000
Property values
11824
13542
12793
12122
13705
13179
11725 14529
14937
13542
Toughness (N.m)
7679
7707
8216
7313
8332
7432
7363 9264
9318
8424
Stiffness (kN.m²)
0
50
100
150
200
250
Strain (µm/m)
CC (mono)
MO-S 0.3% MO-S 0.5%
ST-PP 0.3% ST-PP 0.5%
ST 0.3% ST 0.5%
ST 1.4% (CEM)
Concrete Reinforcement
18000
-6000
-4000
-2000 0
2000
4000
6000
8000
10000
12000
14000
16000
Load(kN)
Load vs. strains (2 bars)
Reinforcement and concrete strains
Repaired / mono CVC beams - reinforcement strains 80% to 120% (mean of 99%)
concrete strains 70% - 135% (mean of 96%)
0
500
1000
1500
2000
2500
3000
µstrain
2300
2383
1838
2414 2734
2403
2366
2280
2092
1926
Reinforcement (tension)
800
615
573
1067
903
884
841
748
530 731
Concrete (compression)
Crack pattern appraoch
CVC (mono. ref.)
SCC
SCC3
Crushing
Crack pattern approach
CVC (mono. ref.)
MO-S 0.3%
MO-S 0.5%
Spalling Crushing
Crack pattern
monolithic CVC beam ST 0.5% beam
Repaired beams had less crack network and crack width than monolithic CVC
beams
Monolithic CVC beams underwent both substantial crushing and spalling at
failure; whereas repaired beams exhibited only crushing
Number of major cracks in monolithic CVC beam is higher than that in repaired
beams
Crack pattern approach
CVC (mono. ref.)
ST-PP 0.3%
ST-PP 0.5%
Spalling Crushing
Crack pattern approach
CVC (mono. ref.)
ST 0.5%
ST 0.3%
ST 1.4% (CEM)
Spalling Crushing
Overall structural performance
Beam
Crack Load(kN)
Yield Load(kN)
Ultimate Load(kN)
Reinf.Strain(µm/m)
Concrete strain (µm/m)
Crack widh (mm)
Toughnrss(N.m)
Stiffness (kN.m²)
CVC (ref.) 45 153 216 2300 -800 0.62 11824 7679
SCC 50 148 230 2383 -615 0.183 13542 7707
SCC3 (3 bars) 50 213 267 1838 -573 0.187 12793 8216
MO-S 0.3% 56 150 206 2414 -1067 0.283 12122 7313
MO-S 0.5% 58 151 213 2734 -903 0.231 13705 8332
ST-PP 0.3% 55 157 216 2403 -884 0.366 13179 7432
ST-PP 0.5% 57 152 204 2366 -841 0.374 11725 7363
ST 0.3% 65 169 230 2280 -748 0.286 14529 9264
ST 0.5% 60 176 227 2092 -530 0.204 14937 9318
ST 1.4% (CEM) 62 182 224 1926 -731 0.094 13542 8424
Overall structural performance
Greater area refers to
better performance Crack load
Reinforcement strain
Crack width
Stiffness Yield load
Ultimate load
Concrete strain
Toughness
Overall structural performance
0.32
0.41
0.630.51
0.41
0.87
0.971.00
Example of beam ST 0.3%
Area×E-4= 12059
Overall structural performance
ACI 318 [2008] CSA-A23.3-06 AASHTO [2005] ACI 363 [2008]
Beam Service lo
ad(k
N)
∆ex
p(m
m)
∆exp/ ∆the
Mea
n
C.O
.V.
∆exp/ ∆the
Mea
n
C.O
.V.
∆exp/ ∆the
Mea
n
C.O
.V.
∆exp/ ∆the
Mea
n
C.O
.V.
Monolith
ic aCVC1 92 4.2 1.38
1.37
24
1.33
1.32
23
1.40
1.37
26
2.35
2.52
33
CVC2 89 2.9 1.02 0.98 1.04 1.80
SCC 90 3.8 1.90 1.79 1.98 3.97
bMO-S 0.5% 100 3.9 1.51 1.46 1.46 2.81
ST-PP 0.5% 104 3.8 1.37 1.33 1.34 2.49
ST 0.5% 115 3.6 1.03 1.01 1.01 1.72
Rep
air
aSCC 89 4.0 2.64
1.80
25
2.45
1.74
22
2.76
1.78
24
5.96
3.46
34
SCC3 128 5.4 1.75 1.76 1.80 2.67
b
MO-S 0.3% 95 4.5 2.10 2.00 1.90 4.05
MO-S 0.5% 91 3.7 1.83 1.74 1.78 3.71
ST-PP 0.3% 94 4.4 2.12 2.03 1.94 4.17
4.182.04ST-PP 0.5% 91 4.3 2.08 1.97
ST 0.3% 101 3.8 1.47 1.43 1.34 2.65
ST 0.5% 106 3.8 1.26 1.23 1.24 2.22
ST 0.5% (d) 101 4.3 1.52 1.47 1.42 2.62
ST 1.4% 109 4.5 1.24 1.30 1.62 2.40
a: Fibrous beams; b: Non fibrous beams
Deflection predictions (monolithic vs. repair beams)
δexp/δthe(1)
CodeACI 318
[2008]
CSA-A23.3-
06
AASHTO
[2005]
ACI 363
[2008]
Beams
Mea
n
C.O.V.
Mea
n
C.O.V.
Mea
n
C.O.V.
Mea
n
C.O.V.
6 Monolithic 1.37 24 1.32 23 1.37 26 2.52 33
10 Repair 1.80 25 1.74 22 1.78 24 3.46 34
(1) Deflection values corresponding to 60% of yield load value.
Deflection predictions(monolithic vs. repair beams)
Inconservative deflection values with all code provisions (the codes do not provide a margin of security.)
Better correlation of δexp/δthe with monolithic beams than repairdones
Better correlation with CSA-A23.3-06 code and lower correlationwith ACI 363
Mean δexp/δthe of all used codes was 1.64 for repair ST 1.4% vs. 2.24 for all other repair beams du to high fiber volume used in this CEM.
Deflection predictions(monolithic vs. repair beams)
Deflection predictions (non-fibrous vs. fibrous beams)
ACI 318 [2008] CSA-A23.3-06 AASHTO [2005] ACI 363 [2008]
Beam Service lo
ad(k
N)
∆ex
p(m
m)
∆exp/ ∆the
Mea
n
C.O
.V.
∆exp/ ∆the
Mea
n
C.O
.V.
∆exp/ ∆the
Mea
n
C.O
.V.
∆exp/ ∆the
Mea
n
C.O
.V.
Non-fib
rous
c
CVC1 92 4.2 1.38
1.74
35
1.33
1.66
33
1.40
1.80
36
2.35
3.35
50
CVC2 89 2.9 1.02 0.98 1.04 1.80
SCC 90 3.8 1.90 1.79 1.98 3.97
2.76d
SCC 89 4.0 2.64 2.45 5.96
SCC3 128 5.4 1.75 1.76 1.80 2.67
Fib
rous
c
MO-S 0.5% 100 3.9 1.51
1.59
24
1.46
1.54
22
1.46
1.55
21
2.81
3.00
29
ST-PP 0.5% 104 3.8 1.37 1.33 1.34 2.49
ST 0.5% 115 3.6 1.03 1.01 1.01 1.72
d
MO-S 0.3% 95 4.5 2.10 2.00 1.90 4.05
MO-S 0.5% 90 3.7 1.83 1.74 1.78 3.71
ST-PP 0.3% 94 4.4 2.12 2.03 1.94 4.17
ST-PP 0.5% 91 4.3 2.08 1.97 2.04 4.18
ST 0.3% 101 3.8 1.47 1.43 1.34 2.65
ST 0.5% 106 3.8 1.26 1.23 1.24 2.22
1.47 1.42 2.62ST 0.5% (d) 101 4.3 1.52
ST 1.4% 109 4.5 1.24 1.30 1.62 2.40
c: Monolithic beams; d: Repair beams
δexp/δthe(1)
Code ACI 318
[2008]
CSA-
A23.3-06
AASHTO
[2005]
ACI 363
[2008]
BeamMea
n
C.O.V.
Mea
n
C.O.V.
Mea
n
C.O.V.
Mea
n
C.O.V.
5 Non-fibrous 1.74 35 1.66 33 1.80 36 3.35 50
11 Fibrous 1.59 24 1.54 22 1.55 21 3.00 29
(1) Deflection values corresponding to 60% of yield load value.
Deflection predictions(non-fibrous vs. fibrous beams)
Inconservative deflection values with all code provisions
ACI 363 underestimates highly deflection value
Better correlation of δexp/δtheo with fibrous beams than non-fibrous ones
Better correlation with CVC type
Predicted deflection is more correlated with beam repaired with FR-CEM
Deflection predictions(non-fibrous vs. fibrous beams)
Stiffness predictions(monolithic vs. repair beams)
Rexp/Rthe
Code ACI 318
[2008]
CSA-A23.3-
06
AASHTO
[2005]
ACI 363
[2008]
Beams
Mea
n
C.O.V.
Mea
n
C.O.V.
Mea
n
C.O.V.
Mea
n
C.O.V.
6 Monolithic 0.61 23 0.67 22 0.60 24 0.34 29
10 Repair 0.46 21 0.51 20 0.45 22 0.24 29
Stiffness predictions(non-fibrous vs. fibrous beams)
Rexp/Rthe
Code ACI 318
[2008]
CSA-A23.3-
06
AASHTO
[2005]
ACI 363
[2008]
Beams
Mea
n
C.O.V.
Mea
n
C.O.V.
Mea
n
C.O.V.
Mea
n
C.O.V.
5 Non-fibrous 0.49 36 0.54 33 0.48 37 0.28 43
11 Fibrous 0.53 22 0.59 21 0.51 21 0.28 30
P exp(kN)
P ACI318 (kN)
Pexp/PACI318
Mea
n
C.O
.V.
P ACI544 (kN)
Pexp/ PACI544
Mea
n
C.O
.V.
M
NC 45 55 0.82
0.85
7.26
-- --
0.69
36.98SCC 55 73 0.75 -- --
ST 0.5% 58 66 0.88 101 0.59
MO-S 0.5% 58 66 0.88 47 0.50
ST-PP 0.5% 60 67 0.90 33 0.98
R
SCC 54.8 73.2 0.75
0.83
18.92
-- --
1.31
65.88
SCC3 38.8 73.2 0.53 -- --
PP-1 0.3% 44.0 67.1 0.66 26.3 1.67
PP-1 0.5% 55.9 69.5 0.81 47.2 1.19
ST-PP 0.3% 57.6 67.8 0.85 18.4 3.13
ST-PP 0.5% 55.1 66.5 0.83 33.2 1.66
ST 0.3% 61.0 66.2 0.92 52.9 1.15
ST 0.5% 67.0 64.9 1.03 101.0 0.66
ST 0.5% (d) 55.0 62.5 0.88101.0 0.54
126.0 0.51ST 1.4% 64.3 65.0 0.99
Crack load predictions(monolithic vs. repair beams)
ACI 318 code provides better predictions for crack laod than ACI 544 code
Pexp/Pthe
Code ACI 318
[2008]
ACI 544
[2008]
Beams
Mea
n
C.O.V.
Mea
n
C.O.V.
6 Monolithic 0.85 7
0.69 37
10 Repair 0.83 19 1.31 66
Crack load predictions(monolithic vs. repair beams)
ACI 318 provided the best predictions for crack load
Workability
characteristics & test
methodsDeformability
Passing ability
Filling capacity
Stability
Rheology
Consolidation of SF-
FR-SCC
Hardened propertiesCompressive strength
Splitting tensile strength
Avg. residual strength
Drying shrinkage
Restrained shrinkage
Flexural creep
Structural performanceMonolithic beams
Repaired beams
Testing and performance of FR-SCC
1.
Development
of mix design
of FR-SCC
2. Necessary
modifica-
tions to
workability
tests
3. Mechanical
properties (f’c,
f’sp, Ec, and fr)
Scope of Research
4. Drying
shrinkage
5. Restrained
shrinkage
6. Flexural
creep7. Durability 8. Repair
methodo-logy
10. Flexural
perfor-mance
of monolithic
and repaired
beams
9. Consolida-
tion of
SWC/FR-
SWC
Load Frames for Flexural Creep
Adjustments before
measurements
Drying shrinkage
Mechanical
properties Reference beam
Loaded Mirror Frame System Under Four-Point Bending
Test
Basis
Supports
Bolt
Upper beam
Lower beam
Principal lever
Lower roller
Load beam4 3 2 1
Secondary lever
Square plate
Steel rod
2 columns
Roller supports
Stems & chain
Ball
Load
Fiber Types and Characteristics
MO-S MU-S STMI-MA ST-PP
Synthetic
92% steel +
8% polypropylene
Hybrid Metallic
Lf (mm) 40 50 20 and 50 5-15 and 42 30
Lf / df 90 < 100 74 < 100 84 < 100 47 < 100 55 < 100
Ef (GPa) 9.5 5 7.2 (macro
portion)
203 (steel portion) 200
Shape Straight Straight Tissue-crimped Micro-crimped Hooked
20% micro +
80% macro
Monofilament Multifilament
• 1 day in formwork (beams) and molds (cylinder and prisms
specimens)
• 6 days under wet burlap and plastic sheets (beams and
cylinders) and in wet curing (drying shrinkage prisms)
• Up to 16 months in a temperature-and humidity-controlled room
at 23 ± 2 oC and 50% ± 4% RH
Curing Method
+ or
0
3
6
9
0 60 120 180 240 300 360 420 480
Time (day)
Deflection (mm)
SCC ST 0.5%MU-S 0.5% MU-S 0.5%-EASCM ST 0.8% CVC ST 0.5%
1
2
3 2
43
2
1
1
2
31
Long-Term Deflection
1: 5 kN (in av., Msus = 0.35 Mcr) 2: 16 kN (in av., Msus = Mcr)
3: 23 kN (in av., Msus = 1.4 Mcr) 4: 30 kN (in av., Msus = 1.9 Mcr)
Msus: Sustained moment Mcr: Cracking moment
0
500
1000
1500
2000
0 60 120 180 240 300 360 420 480
Age (day)
Steel µstrain
SCC ST 0.5%MU-S 0.5% MU-S 0.5%-EASCM ST 0.8% CVC ST 0.5%
Long-Term Reinforcement Strains
0
500
1000
1500
2000
2500
3000
0 60 120 180 240 300 360 420 480
Age (day)
Concrete µstrain
SCC ST 0.5%MU-S 0.5% MU-S 0.5%-EASCM ST 0.8% CVC ST 0.5%
Long-Term Concrete Strains
0.00
0.10
0.20
0.30
0.40
0.50
0 60 120 180 240 300 360 420 480
Age (day)
Crack width (mm) SCC
ST 0.5%MU-S 0.5%MU-S 0.5%-EACVC ST 0.5%SCM ST 0.8%
2
4 3
2
13
31
Long-Term Crack Width
Overall performance for Long-Term Deflection
at 23 kN
0.18
0.93
1.661.25
0.000.00
1.00
2.00
SCC
MU-
S 0.
5%
MU-
S 0.
5%-E
A
ST 0
.5%
SCM
ST
0.8%
Relative overall performance
2.85 0 00
SCM ST 0.8% 360 d-deflection
(×2)
360-d concr. strain
(×3)
360 d-reinf. strain
(×1)
360 d-crack width
(×3)
Relative performance vs. CVC ST 0.5%
Controlled-load bending test on
reference beams Load-controlled loading system
Instantaneous Four-Point Bending Test for Reference
Beams
2 strain gauges for concrete
500 500 150 500 150 P/2 P/2
2 strain gauges for reinforcement
180
2 LVDT 750 750
2 LVDT for cracks
Load and Strain-Control Systems for Instantaneous
Four-Point Bending Test for Reference Beams
Deflection
0
20
40
60
80
0 5 10 15 20 25Deflection (mm)
Load (kN)
SCC ST 0.5%
MU-S 0.5% MU-S 0.5%-EA
CEM ST 0.8% CVC ST 0.5%
Reinforcement and Concrete Strains
0
20
40
60
80
-5000 0 5000 10000 15000 20000
µstrain
Load (kN)
SCCST 0.5%MU-S 0.5%MU-S 0.5%-EACEM ST 0.8%CVC ST 0.5%Steel Concrete
Crack Width
0
20
40
60
80
0 1 2 3 4
Crack width (mm)
Load (kN)
SCC
ST 0.5%MU-S 0.5%
MU-S 0.5%-EACEM ST 0.8%
CVC ST 0.5%
Overall Performance for Instantaneous Deflection
(Verification at 23 kN : 1.4 Mcr)
Relative performance vs. CVC ST 0.5%
0.00
1.99 2.13 2.03
1.12
0.00
1.00
2.00
3.00
SCC
MU-
S 0.
5%
MU-
S 0.
5%-E
A
ST 0
.5%
SCM
ST
0.8%
Relative overall performance
3.00 0
0
0
SCM ST 0.8% Deflection (×2)
Concr. strain (×3)
Reinf. strain (×1)
Crack width (×3)
FR-SCC exhibits good performance in the fresh and hardened
states and is suitable for repair applications
Repair beams exhibited better overall structural performance than
monolithical beams made with CVC
Repair beams with steel fibers had better performance than the
other beams repaired with SCC containing synthetic and hybrid
fibers both for 0.3% and 0.5% fiber volumes
Incorporation of steel fibers in SCC can decrease mid-span
deflection (up to 25%), strain in concrete (30%), strain in steel
reinforcement (20%), and crack width (80%)
Major findings
• Performance in flexural creep (long term) corresponds to:
– instantaneous flexure performance (concrete/steel strain,
deflection, and crack width)
– restrained shrinkage performance (time-to-cracking, crack
width, ring micro-strain at cracking moment, and shrinkage
under sealed and unsealed conditions)
Overall performance of FR-SCC with steel fibers is 25% greater
than FR-CVC
Major findings for flexural creep
Conclusions
• Cracking of SCC (0.48 mm) > ACI 318-11 cracking limits (0.3 to 0.4 mm) >
cracking of FR-SCC and FR-SCM (0.09 to 0.19 mm)
• FR-SCC + EA � best combination (improvement in overall performance by up
to 80%). AE can reduce drying shrinkage (up to 17%), mid-span deflection
(23%), concrete strain (10%), steel reinforcement strain (12%), and crack width
(40%)
Conclusions
• FR-SCM (Vf = 0.8%) can resist well cracking, despite high drying shrinkage
due to absence of coarse aggregate
• Stress relaxation can lead to reduction of steel reinforcement strains (up to
70%), concrete strain (15% to 30%), crack width (25% to 65%), and mid-
span deflection (20% to 45%)
• Best overall performance for flexural creep: [FR-SCC + EA] > [FR-SCC] >
FR-SCC. Overall structural performance of FR-SCC (with/without EA)
under flexural creep can vary between 5 to 10 times that of SCC without
fibers
Owners:
Material Suppliers:
Engineering Firms:
Testing Labs:
Industrial Research Chair on High-Performance
Flowable Concrete with Adapted Rheology (2008-13)
Inspecsol
Prefab: