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Pledge of Allegiance
I pledge allegiance to the Flag of the United States of America, and to the Republic for which it stands, one Nation under God, indivisible, with liberty and justice for all.
Acknowledgements
www.greencoastalstructures.com
www.miamidade-asce.org
GREEN COASTAL STRUCTURES
Green Coastal Structures was founded to implement FRP technology and SEACRETE® in coastal structures;
Green Coastal Engineering is a licensed and insured design and consulting firm specializing in FRP reinforced concrete structures providing cutting-edge design solutions to coastal engineering problems
Green Coastal Technologies offers SEACRETE® and SEABAR® (selection of quality-tested durable FRP concrete reinforcing rebars available on the market screened by our team of material scientists and engineers)
OUR LEADERSHIP
Antonio Nanni, Ph.D., PE, FACI, FASCE
Honorary Director (Pro bono)
Hany Jawaheri Zadeh, Ph.D., PE
Principal
Morteza Khatib, Ph.D.
Principal
South Florida COPRI
CoastsOceansPortsRiversInstitute
Tri-County Institute Comprising:Miami-Dade ASCE BranchBroward ASCE BranchPalm Beach ASCE Branch
For ideas on events, topics, or sponsorship opportunities please contact copri@miamidade-asce.org
Florida Infrastructure Report Card
If you are able to volunteer, please contact copri@miamidade-asce.org
NEXT GENERATION COASTAL CONCRETE STRUCTURES WITH NON-CORROSIVE FRP REINFORCING REBARS
MORTEZA KHATIB, Ph.D.
GREEN COASTAL STRUCTURES
NOVEMBER 6, 2019
OUTLINE
INTRODUCTION TO FRP CONCRETE REINFORCING
BARS
HOW TO DESIGN WITH FRP BARS
FRP-REINFORCED CONCRETE STRUCTURES IN STATE OF
FLORIDA
POTENTIAL OPPORTUNITIES TO IMPROVE THE SUSTAINABILITY
OF COASTAL STRUCTURES
PROBLEM = CORROSION
The global cost of corrosion is estimated to be US$2.5 trillion, which is equivalent to 3.4% of the global GDP (2013).
HOW TO AVOID CORROSION
Admixtures/Design low permeable concrete
Increase cover/coatings
Cathodic protection
Stainless steel/ChromX
Coated steel rebars
EPOXY COATED STEEL REBARS
GALVANIZED STEEL REBARS
Accelerated corrosion
Galvanic corrosion
Estimated to add only 5 more years to the service life of the structure
WHY NOT ELIMINATING CORROSION ONCE AND FOREVER?
FIBER REINFORCED POLYMER CONCRETE REINFORCING REBARS
Glass Fiber Reinforced Polymer (GFRP) Bars
Basalt Fiber Reinforced Polymer (BFRP) Bars
Carbon Fiber Reinforced Polymer (CFRP) Bars
WHAT IS FRPREBAR?
FRP rebars are made of Fibers embedded in Resin matrix
Fibers provide strength and durability
Resin holds fiber together, transfer loads between fibers, and protects from abrasion and environment
PRODUCTION PROCESS
KEY BENEFITS
100% corrosion resistant: no need for 3” cover, Corrosion inhibitor, sealant
Lightweight (1/4 the weight of steel): saving in transportation, labor, and carbon footprint
Superior tensile strength (80 – 175 ksi)
Cost effective: saving in construction, maintenance, and repair cost over the service life of structure
Provides opportunities for implementing more environmentally favorable concrete (SEACRETE ®)
LIMITATIONS
No yield (warning) before failure
Lower modulus than steel (45 – 60 GPa)
Can not be bent on the job site
Largest bar size for now is #10
LONG-TERM DURABILITY
PROVEN DURABILITY
According to field performance of existing FRP-reinforced concrete structures over the last 20 years and numerous research studies, the corrosion-resistant nature of this alternative has demonstrated its ability to extend the service life of concrete structures to more than 100 years.
Cores from a 17-year old bridge show no sign of damage
Cores from five concrete structures in Canada 12 to 15 years old showed similar performance
More than 500 projects in US and Canada used FRP rebars
PROVEN DURABILITY
PROJECTS WITH FRP CONCRETE REINFORCING REBARS IN FL
Low Impact Secant-Pile Seawall for protecting SR-A1A along Flagler Beach
PROJECTS WITH FRP CONCRETE REINFORCING REBARS IN FL
HOW TO SPECIFY AND DESIGN WITH FRP REBARS
HOW TO DESIGN, SPEC, AND BUILD
ASTM D7957-17 Defines material specifications
ACI 440.1R-15 Design with FRP rebars
ACI 440.5-08 Construction with FRP rebars
AASHTO LRFD bridge design guide specifications
HOW TO SPECIFY IN FLORIDA
FDOT design guidelines
Materials Manual for FRP bars
DESIGN CONSIDERATIONS
No ductility
Concrete Crushing as Preferred Failure Mode
Lower modulus
CONSTRUCTION CONSIDERATIONS
Lap splices longer
Support chairs at 2/3 conventional spacings
Bid by foot rather than pound
May need multiple pick up points
COST COMPARISONS
FDOT bid estimates:
#8 Steel Rebar: $2.67/ft vs #8 GFRP Rebar: $2.25/ft
POTENTIAL OPPORTUNITIES TO IMPROVE THE SUSTAINABILITY
SEACRETE ® Using seawater for mixing instead
of freshwater
Replacing natural aggregate in concrete with Recycled Concrete Aggregate and Recycled Asphalt Pavement
Replacing higher amount of cement with byproducts such as Slag and Fly Ash
Using low carbon cement
PROBLEMS
Insufficiency of drinking water for over half of the population of the world by 2025
600 Billion gallons of freshwater per year for concrete production
Cement production contributes 6% of annual global CO2
Aggregate mining has significant environmental impact
RESEARCH PHASE
International research project led by the University of Miami (SEACON)
Data from literature is very promising with corrosion as the only concern
Superior performance of concrete mixed with seawater in marine environment compared with conventional concrete
This attributed to higher degree of hydration and lower chemical gradient between SEACRETE® and surrounding seawater
Support marine ecosystems with more favorable pH and leveling the chemical gradient
SEACRETE ® REDEFINING
SUSTAINABLE CONCRETE
Conserves 100 gallons of freshwater per cubic yard
Conserves energy and natural resources
Reduces waste production and heavy landfill contributions
Reduces cement content due to higher early age strength
Reduces the carbon-foot print of the structure
Provides a more tolerant habitat for marine life
Reduces the environmental impact of concrete infrastructure
Durable in marine environment
DEMO PROJECTS
iDOCK
SEACRETE ® and SEABAR ®
2500 Gallons of freshwater were conserved
Estimated service life of 100 years
Almost no maintenance will be needed over the service life
HALLS RIVER BRIDGE
CONCLUSIONS
Eliminate corrosion in coastal concrete structures once and forever
by replacing steel rebars with FRP rebars
Complete set of materials specification, design and
construction guides are available for FRP concrete reinforcing rebars
Many concrete structures have been built with FRP rebars and are
performing well
Provide opportunities for more environmentally friendly and sustainable approaches in
construction
THANK YOU
EXAMPLE OF MATERIAL PROPERTY
Tensile Strength
Guaranteed Ultimate Tensile Strength: f*fu
Design Strength ffu=Ce x f*fu
Shear Lag (i.e., size effect)
HOW TO TIE REBARS
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