1. Polymers in Civil Engineering
“Poly” “meros” = many parts
Monomer = non-linked “mer” material
Polymers = long continuous chain molecules formed from repeated sequences of small organic units (mers). molecular weight in excess of 10,000.

2. Polymerization
the use of heat, pressure or a chemical catalyst to link monomer material into polymer chains.

3. Plastic Types Thermo plastic Thermosetting plastic
a polymer material that cannot be reformed after manufacturing
cross linked chain networks
less creep, isotropic
good structural properties
injection molded
Thermo plastic
a polymer that can be remolded after manufacturing.
softens upon reheating
substantial creep, isotropic properties
extrusion (PVC pipe) or molding (PET soda bottles)

4. Natural Polymers
· wood
· leather
· cotton
· rubber
· wool
· asphalt

5. Manufactured Polymers
Epoxy (thermosetting)
Polyesters (thermoplastic or thermoset)
Sulfur Concrete (thermoplastic)
Methyl Methacrylate (MMA)
Polyurethane
Polystyrene (thermoplastic)
Polyvinyl chloride, PVC (thermoplastic)
Polyethylene (thermoplastic)

6. Epoxy (thermosetting)
Physical Properties
Strength and Moduli vary with temperature and formulation
Thermal coefficient greater than concrete
Brittle behavior (more brittle than concrete)
Excellent adhesion - tenacious bond
High tensile and compressive strength
Highly resistant to chemical attack and wear

7. Epoxy Disadvantages and limitations
Properties are very sensitive to mixing and proportioning procedures
Some cannot be used in moist environments
Strong Allergenic, safety
Some have strong oder prior to polymerization
Physical properties are substantially different from other materials

8. Epoxy
Applications
Adhesive (old concrete to new concrete, welding cracked concrete, bonding diverse materials)
Patching voids
Durable overlays and coatings

9. Polyesters Thermoplastic or Thermoset Physical Properties
Strength and Moduli vary with temperature and formulation
Thermal coefficient greater than concrete

10. Polyesters Advantages Disadvantages and Limitations
Good Chemical Resistance
Easy to use
Good strength
Good ductility
Inexpensive
Disadvantages and Limitations
Some have marginal bond quality
More expansion and shrinkage than concrete

11. Applications of Polyester
· Floor coatings
· Protective coatings
· Adhesive bonder or sealer
· Binder for fiberglass or artificial wood
· Sealer for Epoxy injection
· Anchoring for drilled holes
· Binder for polymer mortar

12. Sulfur Concrete (thermoplastic)
Physical Properties
Modulus of Elasticity similar to concrete
Thermal expansion greater than concrete
Advantages
Exceptional chemical resistance
Cold joints preventable
Rapid Strength gain 2 h; 24 h)
High strength (7000 psi)
Will set below freezing

13. Sulfur Concrete Disadvantages Applications Requires special equipment
Special handling required - high temperature (280°F)
Will melt at 246°F
Few applicators
Applications
High chemical resistance floors, etc.
Rapid pavement repair or construction

14. Methyl Methacrylate (MMA)
Thermoset
Physical Properties
clear or any color
thermal expansion higher than concrete
low viscosity (< water)
high strength

15. MMA Disadvantages Advantages expensive hazardous (fire) odor
Rapid Strength
Good bond to dry surfaces
Easy to mix
Pre-packaged mixes
Impermeable to water
resistance to acids
excellent abrasion resistance
Disadvantages
expensive
hazardous (fire)
odor
more shrinkage than concrete

16. MMA Applications Plexiglas Pavement of bridge decks
Thin Overlays (3/16"+)
Impregnation
precast elements

17. Polystyrene (thermoplastic)
Advantages
water resistant
dimensional stability
inexpensive
Disadvantages
low tensile strength
low modulus
poor heat resistance
poor weather resistance
brittle, low toughness

18. Polyvinyl chloride, PVC
Thermoplastic
Physical Properties
Tensile MPa ( psi)
Compressive MPa ( psi)
% elongation
t = 75 x 10-6 in./in./°C
E = 3.6 Gpa (5 x 105 psi)

19. PVC Advantages Disadvantages excellent insulator diverse applications
chemical resistance
long-term stability
flame resistant
weather resistant
Adhesion to glass
resistance to oil
Disadvantages
low modulus
Moisture sensitivity in production

20. PVC Applications pipe raincoats window frames and moldings
electrical cables
floor tiles
siding

21. Polyethylene (thermoplastic)
Physical Properties
E = .13 GPa (.19 x 105 psi)
t = 1.0 x10-4/°F
tensile strength 13.8 MPa (2 ksi)
Advantages
tough, durable, weather resistant
chemical and moisture resistance
excellent electrical properties

22. Polyethylene Applications sheet plastic, membranes, liners
pipe, electrical conduit
tanks, bottles

23. Polyurethane Physical Properties Advantages
Sensitive to temperature and RH
low elastic moduli ksi
Advantages
Resistant to Chemicals
lightweight and resistant to wear
Closed Cell material when used with foams
Cryogenic performance

24. Polymer Composites
An Overview

25. Composites with Thermoplastics
Glass Fiber Composites (20-40% wt)
Monofilament
Braided Strand
Chop Fiber
Polymer
Polypropylene (PP), Polycarbonate (PC), Polyethylene Terephthalate (PET), Polybutylene Terephthalate (PBT), Nylon

26. Typical Properties ey E, GPa Ft, MPa PP 5 70-90 0.02 PC & PBT 8 120
Aramid
80-170
3500 -
Carbon
34-800
5000
Steel
200
400
0.002
Most of these materials have a range of properties, depending on manufacturing and design.

27. What is FRP? FRP stands for Fiber Reinforced Plastic
FRP is used in structural shapes, repair materials or as reinforcement for concrete
FRP is a composite material consisting of artificial fibers encased in a resin matrix

28. Materials Used in FRP Fiber Types Resin Types Resins are thermosetting
Glass
Poly-Vinyl Alcohol (PVA)
Carbon
Aramid (Kevlar)
Resin Types
Epoxy
Polyester
Resins are thermosetting

29. Manufacture of FRP Rods
Pultrusion
Enables a high percentage of fibers to be included in the cross section
Braiding
Creates surface deformations which enhance the FRP to concrete bond
Hybrid Rods

30. Engineering Properties of FRP
High Tensile Strength
On average, the tensile strength of FRP is 10% to 500% greater than steel
Low Moduli of Elasticity
With the exception of Carbon rods, FRP has only 1/10 to 1/2 the modulus of steel
Linear Stress-Strain Relationship

31. Applications of FRP Reinforcement bars for Concrete
Prestressing Tendons for Concrete Members
FRP sheets can be used to increase flexural strength in weakened or underdesigned members

32. Advantages of FRP Will Not Corrode In Field Conditions Lightweight
Strong in Tension
Methods of Construction Same as Steel Reinforcement

33. Disadvantages of FRP Low Moduli of Elasticity
Cannot be Shaped in the Field
More Expensive than Steel
Coefficients of Thermal Expansion are Different than Those of Steel or Concrete

34. Conclusion
FRP Reinforcement is an Engineered Material that Shows Great Promise In the Future of Civil Engineering