Preservation of Hopkins Street Bridge via externally bonded prestressed CFRP laminates
Title:
Preservation of Hopkins Street Bridge via externally bonded prestressed CFRP laminates
Author:
Zoghi, M. Foster, D. C.
Appeared in:
Bridge structures
Paging:
Volume 3 (2007) nr. 2 pages 133-146
Year:
2007-06
Contents:
Several fascia beams of an existing prestressed concrete box-girder bridge, located in the City of Defiance, Ohio, USA were severely deteriorated due to the influence of de-icing salt applied during wintertime. An in-depth visual inspection and subsequent full-scale load tests were conducted to identify the extent of deterioration. A strengthening strategy was devised involving advanced carbon fiber reinforced polymer (CFRP) composite strips, post-tensioned via the Stress Head system that was developed and patented in Switzerland. The technique, the first of its type in the USA, offers numerous advantages over conventional repair and rehabilitation methods. The inherent attributes of this innovative approach include lighter weight for easy handling, lower loss of prestress due to higher initial tensile strain, corrosion resistance laminates, optimal use of high tensile strength of CFRP plates, optimal cost/performance ratio, and increased durability with reduction of crack width and tensile steel strain. The proprietary anchorage for prestressing the laminates, made entirely of CFRP composites, is the hallmark of this novel technique. The project, one of two bridges repaired utilizing this approach, was sponsored by the Federal Highway Administration (FHWA) through the Innovative Bridge Research and Construction (IBRC) Program. The IBRC Program promotes the use of new materials and construction techniques for the repair, rehabilitation, replacement, or new construction of bridges and other structures. The design and construction of the strengthening system, adopted to upgrade the Hopkins Street Bridge, will be presented in this paper.
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