A railing can be defined as "a barrier along the sides of a bridge, usually made of concrete or steel, which is intended to prevent vehicles and/or pedestrians from falling over the side of the bridge." Various types of railing have been utilized through the years, but the materials are generally either concrete or steel. If concrete, the typical type built during the Interstate years incorporated a safety curb and parapet topped with aluminum railing. Much of this railing has been upgraded with the current style of deflective parapet. If steel, the most common type used since the 1970s has been deep beam guardrail with tubular backup mounted on 6" wide flange posts on 6'-3" centers. The posts are mounted on the side of the bridge with 4 - 1 1/2" bolts. All steel components are protected against corrosion by galvanizing.
The preventive maintenance recommendations are:
Typical Deflective parapet
Typical Safety Curb, Parapet and Aluminum railing
- Wash off the inside face of the railing (in the splash zone) when washing the decks every spring.
- Seal the top and inside face of the parapet with a silane or siloxane clear sealer (once every 5 years). The ODOT standard two coat (epoxy/urethane) sealer may also be used, but are more expensive and difficult to use than the silanes/siloxanes (Note: It is not uncommon for the parapets to exhibit vertical cracks at a regular spacing, and it is therefore even more important to keep these cracks sealed by one of the above mentioned methods).
Deep Beam Guardrail With Steel Tubular Backup
- Tighten loose bolts as needed.
- Touch-up damaged galvanizing with zinc paint.