Page 75 - Bridge and Highway Structure Rehabilitation and Repair

50 SECTION 1 ADMINISTRATIVE ISSUES

8. Use of precast concrete railings in place of steel railings.
9. Use of chloride for cold weather causing deck cracking.
10. Improved deck curing techniques.
11. Use of concrete inhibitor aggregates.
12. Use of granite aggregates versus limestone aggregates.
13. Use of Class C fl y ash.
14. Shotcrete and gunnite repairs are ineffective.

2.2.9 Selection of Steel
1. Use of stainless steel.
2. Use of weathering steel with painted beam ends.
3. Galvanized joint hardware.
4. Use of epoxy coated rebars and thicker epoxy coats.

2.2.10 Selection of Composite and Elastomeric Materials
1. Elastomeric bearing pads.
2. Composite reinforcing bars.
3. Expansion joint material for strip seal.
4. Epoxy injection.
5. Use of silicone joint with polymer nosing.
6. FRP sheet reinforcement.

2.2.11 Useful Life of an Overlay
Estimated duration of concrete decks, use in years:

1. Overlay thickness 1.25 to 2.5 inches and corresponding scarification depth of 0.25 to 1 inch.
2. LMC, 19 years (maximum life).
3. Low slump dense concrete, 18 years.
4. Asphalt with membrane, 17 years.
5. Fly ash concrete, 17 years.
6. Silica fume concrete, 16 years.
7. Standard concrete mix, 14 years.
8. Asphalt without membrane, 12 years.
9. Plasticized dense concrete, 11 years.
10. Thin bonded epoxy, 10 years (maximum life).

2.2.12 Effective Deck Drainage
1. Use of deck waterproofi ng membranes.
2. Extension of deck drains below bottom of girder fl anges.
3. Prevention of clogging of deck drains.

2.2.13 Construction-Related Aspects for Rehabilitation
1. Method used for joints.
2. Use of staged construction versus detours for reconstruction.
3. Night time deck and parapet pours.