This document compares traditional steel reinforcement and glass fiber reinforced polymer (GFRP) reinforcement for concrete structures. It notes that steel reinforcement is susceptible to corrosion, a major cause of bridge repairs, while GFRP has superior corrosion resistance but is more brittle and costly. The document describes experimental testing of GFRP reinforced beams and finite element modeling to compare displacements and stress distributions between GFRP and steel reinforcement. It finds that GFRP beams experienced greater displacements as expected but modeling challenges remain in fully replicating experimental results. The conclusions determine that proper stress distributions were achieved and higher neutral axis displacement occurred with GFRP compared to steel reinforcement.

1. Glass Fiber
Reinforcement
Polymer
A Comparison with
Traditional
Reinforcement
Matthew Williams

2. Motivation
- Structural concentration with an
interest in bridge design
- Studied alternative reinforcement
in Advanced Concrete
Technology
- Steel corrosion is a major
infrastructure concern
- Epoxy coating is ineffective and
stainless steel is expensive

3. Traditional Steel Reinforcement
Pros
- Cheap
- Provides ductile failure
- Good strength to
weight ratio
Cons
- Susceptible to corrosion
- Coatings offer little protection
- Cause of majority of bridge
repairs
- Environmental impacts

4. What Is GFRP
- Glass fiber cured in
epoxy resin
- Provides superior
strength in the
longitudinal direction
- Recommended safety
factor of 0.85-0.7 for
flexural design
http://www.build-on-prince.com/glass-fiber.
html#sthash.9iOUBSVO.dpbs

5. Glass Fiber Reinforcement
Pros
- Corrosion resistance
- Lightweight
- 3 times tensile strength
of steel
Cons
- Cost
- Glass fibers do react with
concrete
- Brittle failure
- Availability

6. Comparing Reinforcements
- Adam et al. 2015 experimentally tested 10 GFRP
reinforced beams
- Compared with FEM analysis
- Want to try and replicate displacements that were
achieved.
- Nanni 2003 states that serviceability may be more
important than strength.
- Additionally, went to run FEM analysis comparing
displacement and stress distributions in FRP vs. Steel.

7. Experimental vs. FEM Method

8. Steel vs. GFRP Method

9. Results

10. Results

11. FEM Stress Distribution
GFRP
Steel

12. Conclusions
- Difficult to replicate experimental results with
software
- Proper stress distributions were replicated
- Higher neutral axis was achieved
- GFRP displacements were greater as
expected

13. Questions?

14. References
Adam, Maher A., et al. "Analytical and experimental flexural behavior of concrete beams reinforced with glass fiber reinforced polymers bars."
Construction and Building Materials 84 (2015): 354-366.
Aguiñiga, F., H. Estrada, and J. I. Cruz. "Effects of Cyclic Loading on Structural Performance of Glass Fiber Reinforced Polymer Reinforced
Concrete Elements." Structures Congress 2006@ Structural Engineering and Public Safety. ASCE, 2006.
Karbhari, V. M., et al. "Durability gap analysis for fiber-reinforced polymer composites in civil infrastructure." Journal of Composites for
Construction 7.3 (2003): 238-247.
Nanni, Antonio. "North American design guidelines for concrete reinforcement and strengthening using FRP: principles, applications and
unresolved issues."Construction and Building Materials 17.6 (2003): 439-446.
Sim, Jongsung, and Cheolwoo Park. "Characteristics of basalt fiber as a strengthening material for concrete structures." Composites Part B:
Engineering 36.6 (2005): 504-512.