ENHANCING THE DYNAMIC FRACTURE TOUGHNESS OF...
Transcript of ENHANCING THE DYNAMIC FRACTURE TOUGHNESS OF...
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ENHANCING THE DYNAMIC
FRACTURE TOUGHNESS OF
CONCRETE WITH FIBER
REINFORCEMENT
Nemy Banthia
University of British Columbia
Vancouver, Canada
2013 UBC‐Tongji‐CSRN Symposium, Modern Solutions to Seismic Risk Mitigation: August 19-20, 2013, Vancouver, Canada
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Outline:Fiber Reinforced Concrete
(FRC)
Eco-Friendly Ductile Cementitious Composites (EDCC)
Infrastructure Deterioration and Interest in Durable Cementitious Composites
FRC for Sensing and Smart Structures
Closure
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Fibers for Concrete Use
Carbon
Spectra HDPE fiber
Basalt fiberCellulose fiber Carbon Fiber
Polyester FiberDeformed Steel
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Production of
Fiber Reinforced
Concrete
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Fiber Reinforcement and Crack
Bridging
Fibers
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Applications
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Fiber Matrix Interaction, Mechanisms of
Reinforcement and Bond Optimization
(a) untreated PP plate surfaces.
(b) plasma treated PP plate surfaces.
Contact angle: 80o
Contact angle: 7o
dzdzppwfd
Vw
fL
zf
f
tension )()(),(4/
)(0
cos)2/(
02
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Bending Response: Hardening and Softening
0
300
600
900
1200
1500
1800
0
2
4
6
8
10
12
0 0.02 0.04 0.06 0.08 0.1
0 0.5 1 1.5 2 2.5
Eq
uiv
ale
nt
Be
nd
ing
Str
es
s (
psi)
Deflection (in)
Deflection (mm)
Eq
uiv
ale
nt
Be
nd
ing
Str
es
s (
MP
a)
Vf = 0.23%
ASTM C-1018 Test
Torex Fiber
d = 0.5 mm, L = 32 mm
Concrete mix
f'c = 36 MPa
Vf = 0.8%
MOR
LOP, BOP
Deflection-
Hardening
Deflection-Softening
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Tension: Ecofriendly Ductile Cementitious Composites
(EDCC)
)(1
1)(
21321
f
f
mu
fucriticalff
d
lVV
42
f
fu
mu
f
md
V
Vx
x
dzdzppwfd
Vw
fL
zf
f
tension )()(),(4/
)(0
cos)2/(
02
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ART in
EDCC
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Strain-Rate Effects
Event Strain Rate
Quasi-Static Testing
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Testing at High Strain Rates incl. Impact
Split Hopkinsons
Pressure Bar
Drop Weight Impact
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FIB Formulation (in tension)
(in compression)
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EDCC: 𝜀 Associated with Earthquakes
𝜀 = 10−3/𝑠𝑒𝑐
𝜀 = 10−6/𝑠𝑒𝑐
d/dtSize and Rate Effects
Rate Effects
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Producing Durable Infrastructure
Structures built today
last an average of 37
years ONLY!!
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Influence of Climate Change on Concrete
Structures
Increase in atmospheric CO2 levels from 370 ppm to 1000 ppm
Increased Corrosion Rates
Increased Carbonation
Increase in temperature by over 50C Increased Shrinkage
Porous Microstructure and High Permeability
Increased Corrosion Rates
Increased Water Levels Increased Saturation
Greater Scour
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FRC for Durability : Time to Corrosion Onset
(weeks)
No Loading
15-kN Loading
30-kN Loading
0
10
20
30
40
50
60
70
80
Tim
e to
Co
rro
sio
n O
nse
t (w
eek
)
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FRC for Sensing and Smart Structures
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Structural Health Monitoring
Sensing Data AcquisitionData processingCommunication Damage detectionModeling and Interpretation
Sensor Location and Transmitter
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Crossbow Tri-Axial
Accelerometer Corrosion Sensor
Tilt-Beam Sensor
Fibre optic sensor
Thermocouple
Wind Monitor
Sensors for Structures
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FRC Sensor Development with Carbon Nano Tubes
Resistivity
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Rapid Cyclic Tests and Fractional Change
in Resistance (FRC)
Load
Piezo-Resistive
Cement-Based
Sensor
[FCR]
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Combining Fibers with Nanotubes
Traditional Gauge
Traditional Gauge
PFRC 15% CF
+ 1% MWCNT
PFRC 15%
CF
Gauge Factors
290 for 0.0007
145 for 0.0007
Gauge Factors
410 for 0.0004
110 for 0.0004
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Provencher Bridge, Winnipeg, Manitoba
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Data Acquisition / Control Room
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Thank You!