Project of the Year: Longevity Category
Pile Restoration Lake Pontchartrain Causeway
New Orleans, Louisiana
Submitted by Master Builders, Inc.
During the course of the last 43 years, the Lake Pontchartrain Causeway in New Orleans, Louisiana, has not only held the distinction of being the world’s longest bridge at 24 miles, but has been an interesting study of concrete’s durability in marine environments. When pile encapsulation specimens are tested to failure, the tightly bonded composite transfers load to the concrete and it fails in tension. In this case, the 8500 psi (58.4 MPa) concrete, typical of the centrifugally cast cylinder pile, is the weakest link in the composite.
The current Pile Restoration Program began in 1996 and involved encapsulation of 414 piles. Most of the encapsulation work was carried out near or below the waterline, requiring the use of divers working with surface supplied air.