1. Bonded Repair of R/C Bridge Components using FRP Wrapping – McDade Road Bridge over US 40 Peter Chang Bala Balaguru March 23, 2010

2. University of Maryland

3. High Strength Composites Fiber Reinforced Polymers(FRP) Fibers: carbon, glass Matrix: organic polymers Applications: aerospace, ship building, automobiles, rail cars, Concrete structures

4. Common Tow Reinforcements

5. Common Fabric Reinforcements

6. Advantages of FRP High Strength Low unit weight High specific strength Corrosion resistance Used for more than 40 years

7. Major Disadvantage Low resistance to high temperature (fire) Fire hazard in transportation structures, 31% as compared to 37% flooding and 8% earthquake Restricted use in buildings Restricted use in tunnels Coef. of thermal expansion >> concrete Some high temp matrix is highly toxic

8. Applications of Inorganic Polymer in Civil Infrastructure Durable and fire resistant Strengthening; bricks, concrete, reinforced concrete Protective and graffiti resistant coatings Sandwich panels

9. Appearance of Inorganic FRP Compared to Organic FRP Organic FRP Inorganic FRP

10. Superior Properties of Geopolymer First: –Sets at room temperature; non toxic. Second: –higher heat tolerance. Third: –Geopolymers resist all organic solvents (and are only affected by strong hydrochloric acid).

11. Features of the Inorganic Matrix Polysialate (“Geopolymer”) Aluminosilicate Water-based, non-toxic, durable Curing temperature: 20, 80, 150°C Resists temperatures as high as 1000°C Protects carbon from oxidation

12. Alumino-silicates as Binder

13. Polycondensation into poly(sialate) and poly(sialate-siloxo)

14. three dimensional macromolecular edifice

15. Research in Coating Technology

16. Making heat-resistant Geopolymer Composite

17. Application of Technology for Bridge Protection

18. Geopolymer Protective Coating

19. 2-year Old Test Patch

20. Surface Coating of Concrete Uncoated surfaceCoated surface

21. Close-up of Coated Concrete

22. Durability Tests: As Coating Material WET-DRY EXPOSURE (0, 50, and 100 cycles) SCALING EXPOSURE (50cycles) Samples Reinforced with: 2 and 4% discrete carbon fibers 1, 2, and 3 carbon tows 1 and 2 layers of carbon fabric

23. Wet – Dry Durability

24. Peak Load of Samples after Wet-dry Exposure

25. Peak Load of Samples after Scaling Exposure

26. Typical Sample Prior to Test Balsa wood core with inorganic carbon fiber facings Smooth & glossy Sample dimensions: –4 inches wide –4 inches long –¼” inch thick

27. OSU Test on Composite

28. Sample After Fire Testing Facings visibly charred from intense heat Rough surface with minor cracking Sample dimensions change, including weight

29. Failure Pattern No delamination No build-up of shear strain at the interface Strain in fiber comparable to organic matrix

30. Crack Patterns from Flexure Test PC 2IO-1 3IO-1 4IO-2 5IO-2 2O-1 3O-2 4O-1

31. Thank you. pchang@umd.edu (301) 405-1957 www.cee.umd.edu