1. Reinforcement Design and Control of Concrete Mixtures – Chapter 8

2. Overview Why Use Reinforcement in Concrete? Reinforcing Bars Welded Wire Reinforcement Prestressing Steel Fibers

3. Why Use Reinforcement in Concrete?

5. Also used for: Some compression Diagonal tension or shear Internal pressures in circular structures Reducing crack sizes Limit crack widths

6. Steel Reinforcement

7. Reinforcing Bars (Rebar) High tensile strength, strain compatibility Bond between steel and concrete ASTM A615 – commonly grade 60 ASTM A706 – weldable rebar

8. Reinforcing Bars

13. Welded Wire Reinforcement (WWR)

14. WWR

15. Prestressing Steel

18. Fibers

20. Steel Fibers

22. SIFCON

23. Glass Fibers

24. Synthetic Fibers

26. Acrylic fibers – asbestos replacement Aramid fibers – 2.5x stronger than E-glass, 5x stronger than steel, good temperature stability Carbon fibers – high strength and elastic modulus Nylon fibers – good tenacity, toughness, elastic recovery Synthetic fibers also used in stucco and mortar

27. Natural Fibers Used long before other forms of reinforcement ASTM D7375, ASTM D6942 Unprocessed natural fibers Processed natural fibers – wood fibers

28. Multiple Fiber Systems Hybrid-fiber concrete Macro- and microsteel fibers Steel and polypropylene

29. Summary Why Use Reinforcement in Concrete? Reinforcing Bars Welded Wire Reinforcement Prestressing Steel Fibers

30. Questions