ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.
Issue link: http://www.aspiremagazinebyengineers.com/i/306189
The Route 5S over Wallkill bridge uses cast-in-place, reinforced concrete arches with precast concrete spandrel columns, cap-beams, and a precast, prestressed concrete adjacent box beam superstructure. All precast components were made using self- consolidating HSHPC. S TAT E S TAT E C oncrete bridges play a significant role in the transpor tation infrastr uctur e of New York State. Since the early part of the twentieth century, methods for both designing and building concrete bridges have undergone many changes. Generally, concrete bridges have served the state well. There are some cases, however, where early methods that were used have resulted in deterioration. T h e N e w Yo r k S t a t e D e p a r t m e n t o f Transportation (NYSDOT) has developed, and is currently using, technology in concrete bridge design and construction that will significantly reduce corrosion-related deterioration. NYSDOT is in the forefront of utilizing the latest advancements in concrete technology such as high-strength, high-performance concrete (HSHPC), self-consolidating concrete (SCC), ultra-high-performance concrete (UHPC), and internal curing concrete (ICC) for building concrete bridges that are more durable as well as cost effective. reinforced Concrete bridges Many of New York State's aesthetically pleasing open spandrel concrete arch bridges built in the first half of the twentieth century are still in ser vice today and, with proper maintenance, should continue to be for quite some time. One such structure, currently under rehabilitation, is Route 5 over Eighteen Mile Creek in western New York State. This bridge was completed in 1931 and is expected to have at least an additional 25 years of service life after the current rehabilitation is completed. Based on the proven durability and aesthetic appeal of these structures, NYSDOT continues to build reinforced concrete arch bridges whenever appropriate. Two such bridges, recently completed, are Route 5S over Wallkill and Route 30 over Minekill. Both bridges have cast-in- place, reinforced concrete arches and precast, prestressed concrete superstructures, made using self-consolidating HSHPC, above the arch. Even though concrete arch bridges are both durable and attractive, they are relatively expensive to build. NYSDOT built a significant number of less expensive, yet still attractive, reinforced concrete earth-filled arch frame bridges for grade separations during the construction of parkways during the mid- twentieth century. These bridges have been very durable and the vast majority of them are still in service. Some of these bridges have been recently replaced with adjacent precast, prestressed concrete box beams with cur ved soffits to replicate the bridges they replaced. p restressed Concrete bridges NYSDOT started building prestressed concrete bridges in the 1950s, with a few post-tensioned T-beam bridges. Most of the T-beam bridges have already been replaced due to the corrosion of the post-tensioning tendons—a result of insufficient grouting methods in use at that time. The grout, with high water content, left voids in the ducts, which when infiltrated by chloride contaminated deck drainage, led to significant corrosion of the post-tensioning tendons. One remarkable bridge that was completed in 1960, I-81 over Oneida Lake, is worthy of special recognition. From the time of its completion until 2010, this bridge held the record for the longest main span in the world for a precast, prestressed concrete spliced girder bridge at 320 ft. The structure is in good condition overall except that the fascia girders have the bottom tendons corroded at locations where the girders were exposed to deck drainage. The weakened girders are being strengthened with external Concrete Bridges in New York State by Matthew C. Royce, New York State Department of Transportation Route 5 over Eighteen Mile Creek in western New York, is an open spandrel cast-in-place, reinforced concrete bridge completed in 1931. All photos: NYSDOT. NYSDOT started building prestressed concrete bridges in the 1950s. Book_Fall11.indb 46 9/29/11 12:00 PM