United States’ bridges have a median age of 40 years. Today, many of these structures need rehabilitation. Increased traffic and urban congestion demand outside-the-box thinking to accelerate construction. Traffic control is running anywhere from 20 to 40 percent of construction costs. User delays cost thousands of dollars per day in heavy traffic areas. Similar conditions exist in Canada but are often more critical due to our shorter construction season. In 2001, the AASHTO Technology Implementation Group, chose prefabricated bridge elements and systems as one of the innovative technologies that promised the highest payoff. The FHWA, through its Innovative Bridge Research and Construction program and the Resource Center, champions prefabrication for accelerated construction. Their vision is to solve bridge deterioration with accelerated construction through increased prefabrication. AASHTO and FHWA are encouraging prefabrication technology because of the many advantages for bridge owners, engineers, builders, and the traveling public. First, use prefabricated elements or systems to minimize traffic impacts. Precast contractors can perform time-consuming formwork assembly, concrete casting, and curing offsite in the controlled environment of a precast plant. Prefabricated bridge designs are more constructible because the offsite work reduces time onsite. Constraints, such as heavy traffic, extreme elevations, and long stretches over water, and tight urban work zones, are overcome through prefabrication. Safety improves because prefabrication reduces the exposure time for workers and the public who travel through construction zones. Precast elements and systems work well to accelerate both rehabilitation and new construction. Shipment of precast components to the job site reduces impacts on the environment. Finally, prefabricating takes elements and systems out of the critical path of a project schedule. Precast fabricators can produce quality components or systems in a controlled plant environment in much less time than is required on site. Improved quality translates to lower life-cycle costs and longer service life. The paper includes a background on precast concrete bridge construction, an overview of precast concrete deck construction, fabrication transportation and erection, sustainability issues and total precast bridge construction. The benefits of precast prestressed concrete for bridge construction include speed, durability, minimum traffic interruption, assured plant quality, minimum maintenance and attractive designs. New ideas are required to address the dual needs of faster construction and long service life. Some case studies from the United States and Canada offer new ideas on techniques and construction details to achieve the goal of: “Get in. Get out. Stay out.”
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