ENHANCING THE DYNAMIC FRACTURE TOUGHNESS OF CONCRETE WITH FIBER - - PowerPoint PPT Presentation

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

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

Fibers for Concrete Use

Carbon

Spectra HDPE fiber Basalt fiber Cellulose fiber Carbon Fiber

Polyester Fiber Deformed Steel

Production of Fiber Reinforced Concrete

Fiber Reinforcement and Crack Bridging

Fibers

Applications

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

    

  

dzd z p p w f d V w

f

L z f f tension

) ( ) ( ) , ( 4 / ) (

cos ) 2 / ( 2

 

 



Bending Response: Hardening and Softening

300 600 900 1200 1500 1800 2 4 6 8 10 12 0.02 0.04 0.06 0.08 0.1 0.5 1 1.5 2 2.5

Equivalent Bending Stress (psi) Deflection (in) Deflection (mm) Equivalent Bending Stress (MPa)

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

Tension: Ecofriendly Ductile Cementitious Composites (EDCC)

) ( 1 1 ) (

2 1 3 2 1

          

f f mu fu critical f f

d l V V                          4 2

f fu mu f m

d V V x   x

    

  

dzd z p p w f d V w

f

L z f f tension

) ( ) ( ) , ( 4 / ) (

cos ) 2 / ( 2

 

 



ART in EDCC

Strain-Rate Effects

Event Strain Rate

Quasi-Static Testing <10-6 /s Traffic 10-6 – 10-4 /s Gas Explosions 5x10-5 – 5x10-4 /s Earthquake 5x10-3 – 5x10-1 /s Pile Driving 10-2 – 100 /s Aircraft Landing 5x10-2 – 2x100 /s

Testing at High Strain Rates incl. Impact

Split Hopkinsons Pressure Bar Drop Weight Impact

FIB Formulation

(in tension) (in compression)

EDCC: 𝜁 Associated with Earthquakes

𝜁 = 10−3/𝑡𝑓𝑑 𝜁 = 10−6/𝑡𝑓𝑑

d/dt

Size and Rate Effects Rate Effects

Producing Durable Infrastructure

Structures built today last an average of 37 years ONLY!!

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

FRC for Durability : Time to Corrosion Onset (weeks)

No Loading 15-kN Loading 30-kN Loading 10 20 30 40 50 60 70 80 Time to Corrosion Onset (week)

FRC for Sensing and Smart Structures

Structural Health Monitoring

• Sensing
• Data Acquisition
• Data processing
• Communication
• Damage detection
• Modeling and

Interpretation Sensor Location and Transmitter

Crossbow Tri-Axial Accelerometer Corrosion Sensor Tilt-Beam Sensor Fibre optic sensor Thermocouple Wind Monitor

Sensors for Structures

FRC Sensor Development with Carbon Nano Tubes

Resistivity

Rapid Cyclic T ests and Fractional Change in Resistance (FRC)

Load Piezo-Resistive Cement-Based Sensor [FCR]

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

Provencher Bridge, Winnipeg, Manitoba

Data Acquisition / Control Room

Thank You!