Prefabricated Bridge Construction across Europe and America

摘要

Determining the most efficient and economical way to build a new or replacement bridge is not as straightforward a process as it once was. The total cost of a bridge project is not limited to the amount spent on concrete, steel, and labor. Construction activities disrupt the typical flow of traffic around the project and results in additional costs to the public in the form of longer wait times, additional mileage traveled to get around the work zone, or business lost attributable to customers avoiding the construction. The risk of injury to workers because of traffic interactions or construction activities increase with each hour spent at the construction site. Finding a way to shorten the time spent on the jobsite is beneficial to the contractor, the owner, and the traveling public. Prefabricating certain bridge elements reduces the time spent at the construction site and reduces the effects on the road users and the surrounding community. For example, steel beams with composite concrete decks reduce the construction time over cast-in-place concrete superstructures. In some instances, entire structures have been fabricated off-site under strict environmental and quality controls and then shipped to the site and erected in a matter of days instead of months. The total cost of using prefabricated bridge elements (PBE) depends greatly on the scale of the prefabrication. The more that prefabrication is used, the lower the costs. Even under limited use, however, prefabrication is usually comparable to traditional construction techniques. However, when durability and user costs are taken into account, the overall cost may be significantly less than traditional piece-by-piece construction. To improve the competitiveness of prefabricated composite bridges, a European research and development project, ELEM RFSR-CT-2008-00039, was started in 2008. The overall objective of the project is to make prefabricated bridges more competitive through development of new cost-effective, time-efficient, and sustainable bridge structures. The project has started with a knowledge extension, in the form of the workshop on "Composite Bridges with Prefabricated Deck Elements." This workshop was held in Stockholm, Sweden, in March 2009 to share the knowledge and experience gained by agencies around the globe. During the workshop, experiences from Europe and the United States were presented in an effort to promote the use of accelerated bridge construction (ABC) and prefabricated bridge elements.