Chapter 5. Silica-Fume Concrete Projects

1. Chapter 5. Silica-Fume Concrete Projects • Bridge Decks • Parking Structure • High-Rise Columns • HPC Bridge • Shotcrete Rehabilitation • HPC Constructability

2. Bridge Decks -- New Construction and Overlays(Fly Ash and Silica Fume Combination) Chapter Outline

3. Project: Bridge Deck Construction New York State DOT High-Performance Concrete Requirements: Resist chloride ion penetration Minimize cracking

4. Concrete Mixture: Portland cement 500 lb/yd3 Fly ash 135 lb/yd3 Silica fume 40 lb/yd3 w/cm 0.40 Slump 3-4 inches Air 6.5 % Wet cure 7 days

5. Concrete Performance: Rapid chloride permeability: < 1,600 coulombs Compressive strength, 28 days: > 5,400 psi “Results indicated that Class HP decks performed better than previously specified concrete in resisting both longitudinal and transverse cracking.”

6. SI Project: Bridge Deck Construction New York State DOT High-Performance Concrete Requirements: Resist chloride ion penetration Minimize cracking

7. SI Concrete Mixture: Portland cement 300 kg/m3 Fly ash 80 kg/m3 Silica fume 25 kg/m3 w/cm 0.40 Slump 75-100 mm Air 6.5 % Wet cure 7 days

8. SI Concrete Performance: Rapid chloride permeability: < 1,600 coulombs Compressive strength, 28 days: > 37 MPa “Results indicated that Class HP decks performed better than previously specified concrete in resisting both longitudinal and transverse cracking.”

14. Bridge Deck Overlay(High Silica Fume Content) Chapter Outline

15. Project: Bridge Deck Overlay, Ohio DOT Beverly, Ohio Requirements: Resist chloride ion penetration 4,500 psi at 28 days RCP < 1,000 coulombs

16. Concrete Mixture: Portland cement, Type I 700 lb/yd3 Silica fume 70 lb/yd3 w/cm 0.36 Slump 4-8 in. Air 6-10% HRWRA 20 fl oz/cwt WRA, Type D 3 fl oz/cwt

17. Concrete Performance: Rapid chloride permeability 600 coulombs Compressive strength, 28 days 7,000 psi

18. SI Project: Bridge Deck Overlay, Ohio DOT Beverly, Ohio Requirements: Resist chloride ion penetration 31 MPa at 28 days RCP < 1,000 coulombs

19. SI Concrete Mixture: Portland cement, Type I 415 kg/m3 Silica fume 41.5 kg/m3 w/cm 0.36 Slump 100-200 mm Air 6-10% HRWRA 1.3L/100 kg WRA, Type D 165 ml/100 kg

20. SI Concrete Performance: Rapid chloride permeability 600 coulombs Compressive strength, 28 days 48 MPa

27. Parking Structure Chapter Outline

28. Project: Parking Structure General Mitchell Airport Milwaukee, Wisconsin Requirements: Resist chloride ion penetration 2,000 psi at 36 hours 5,700 psi at 56 days

29. Concrete Mixture: Portland cement, Type I 565 lb/yd3 Fly ash, Class C 100 lb/yd3 Silica fume 39 lb/yd3 w/cm 0.35 WRA 12 fl oz/yd3 Slump, maximum 9 in. Additional WRA and HRWRA in SF slurry

30. Concrete Performance: Compressive strength, 36 hours: > 2,000 psi Cores taken at 2 - 10 months averaged < 1,000 coulombs Slump used: 6 - 7.5 in.

31. SI Project: Parking Structure General Mitchell Airport Milwaukee, Wisconsin Requirements: Resist chloride ion penetration 14 MPa at 36 hours 40 MPa at 56 days

32. SI Concrete Mixture: Portland cement, Type I 335 kg/m3 Fly ash, Class C 60 kg/m3 Silica fume 17 kg/m3 w/cm 0.35 WRA 440 mL/m3 Slump, maximum 230 mm Additional WRA and HRWRA in SF slurry

33. SI Concrete Performance: Compressive strength, 36 hours > 14 MPa Cores taken at 2 - 10 months averaged < 1,000 coulombs Slump used: 150- 90 mm

40. High-Rise Columns Chapter Outline

41. Project: Key Bank Tower Cleveland, Ohio Requirements: High ultimate strength, > 12,000 psi High modulus, > 6,800,000 psi Pumpable, 57 stories

42. Concrete Mixture: Portland cement, Type I 685 lb/yd3 GGBFS 285 lb/yd3 Silica fume 80 lb/yd3 w/cm 0.24 Slump, minimum 10 in. HRWRA 30-50 fl oz/cwt WRA, Type A 4 fl oz/cwt

43. Concrete Performance: Modulus > 7,000,000 psi Compressive strength, 28 days > 14,000 psi 56 days > 15,000 psi

44. SI Project: Key Bank Tower Cleveland, Ohio Requirements: High ultimate strength, > 83 MPa High modulus, > 47 GPa Pumpable, 57 stories

45. SI Concrete Mixture: Portland cement, Type I 406 kg/m3 GGBFS 169 kg/m3 Silica fume 47 kg/m3 w/cm 0.24 Slump, minimum 250 mm HRWRA 2.0-3.3 L/100 kg WRA, Type A 260 mL/100 kg

46. SI Concrete Performance: Modulus > 48 GPa Compressive strength, 28 days > 97 MPa 56 days > 103 MPa