with a longer expected life. Conclusions
The Exodermic design used on this project provided the span capacity required and significantly simplified construction details. Lower design stress at welds and punchouts in the grid should provide an “infinite” fatigue life.
On this project, the owner stressed the importance of long term perform- ance, specifying:
High performance concrete in the deck
to reduce its permeability to deicing salts.
Hot-dip galvanized Exodermic deck
Lightweight grid panels arrive at the job site with replacement of the 330,000 s.f.
grid panels before they were shipped to the job site. Rebar was lapped between panels and at the longitudinal splice between stages (except on the approach- es, where threaded dowel bar splice con- nectors were used). This approach saved a substantial amount of field labor, and allowed the project to move along faster.
Despite the weight savings of the new lighter deck, the weight of the concrete barriers would have exceeded the avail- able capacity. NYSBA elected to use lightweight concrete in the barriers. A polymer shell was specified on the road- way side of the barrier to protect the lightweight concrete from road salts and excess moisture and was a substantial aid in forming the barrier. Its highly reflective surface provides an additional measure of safety.
reinforcing steel already tied in place, speeding of bridge deck significantly.
being repaired on site. Asphalt plug joints were used for joints moving less than 1 inch or fixed joints subject only to rota- tion. NYSBA’s experience with plug joints has been excellent in that they effectively seal out moisture and require only minor annual maintenance.
The concrete specified was New York State DOT’s standard DP mix. This mix design is identical to the state’s high per- formance (HP) mix, which is used on all new bridge decks in the state, but with the smaller coarse aggregate required by all grid deck designs. The mix substi- tutes 6% microsilica and 20% fly ash for cement, in order to provide concrete less permeable to deicing salts, and therefore
Hot-dip galvanized reinforcing steel
in the reinforced concrete component of the Exodermic deck.
A polymer shell on the front face of
the new Jersey barrier to protect the inter- nal lightweight concrete from deicing salts and moisture.
Improved joints to seal out moisture
and corrosive road salts.
Adapted from a poster session paper presented at the World Steel Bridge Symposium, Chicago, Illinois, Octobe , 2001, “Rehabilitation of the Kingston- Rhinecliff Bridge over the Hudson River by William J. Moreau, P.E., Chief Enginee , New York State Bridge Authority, and Robert A. Bettigole, P.E., President, Exodermic Bridge Deck, Inc.
The reinforcing cage for the barrier was designed to work with the size and spacing of the grid bars and reinforcing steel in the deck, and to permit all reinforcing to be placed from the top of the deck.
The original expansion joints in the deck were compression seals for the small joints and open steel finger joints for the larger movements. The replacement joints are strip seals for the smaller move- ments and modular joints in lieu of the finger dams. These sealed joints should reduce the level of corrosion of the steel below the deck, and have the capability of
The bright, white polymer shell protects the barrier's lightweight concrete from road salts while railing permits stunning views of the Hudson River.
EXODERMIC BRIDGE DECK, INC. • 60 LONG POND RD, LAKEVILLE, CT 06039 • TEL: 860.435.0300 • FAX: 860.435.4868 • email@example.com