Advantages of Prestressed Concrete Bridges



Owners and designers have long recognized the low initial cost, low maintenance needs and long life expectancy of prestressed concrete bridges. This is reflected in the increasing market share of prestressed concrete, which has grown from zero in 1950 to more than 55 percent today.

This growth continues very rapidly, not only for bridges in the short span range, but also for spans in excess of 150 feet which, heretofore, has been nearly the exclusive domain of structural steel.

The following examples illustrate some of these key advantages of precast, prestressed concrete bridges:

Many bridge designers are surprised to learn that precast, prestressed concrete bridges are usually lower in first cost than all other types of bridges.
Coupled with savings in maintenance, precast bridges offer maximum economy.


The precast prestressed bridge system offered two principal advantages:
it was economical and it provided minimum downtime for construction. Project duration was three weeks.

The state of Minnesota saved more than 16% - a half a million dollars – by planning for a prestressed alternate to a steel bridge.
The 700-foot-long bridge is jointless up to the abutments and is the longest continuous bridge in the state. It also contains the longest single concrete span.

A Minnesota transportation official stated, “Originally, we didn’t think concrete was suited to this… bridge. However, the fabricator showed us it was a viable alternative. Everything went smoothly… we’re well satisfied…”

Precast, prestressed concrete bridge components are easy to erect, particularly when the tops of the units comprise the entiredeck slab to form an “integral deck” or “full-deck” beam.

In a full-deck bridge, the formwork of the super­structure is eliminated. Connections between adjacent units often consist of welding matching plates and grouting continuous keyways. Carefully planned details speed the construction process and result in overall economy.

…but it may be easier and more economical to build new ones, or to utilize precast abutments and wing walls supported on cast-in-place footings. Because precast concrete integral deck bridges with precast abutments can be erected without delay in cold weather, they can be opened to traffic sooner.

Bridge departments are challenged to maintain traffic flow, minimize traffic interruptions, and reduce or eliminate detours during construction projects.
This Florida bridge, damaged in a tanker fire, was completely rebuilt and opened to traffic in 18 days.

The fast construction of precast concrete integral deck bridges is a key advantage. Precast concrete bridges can be installed during all seasons and opened to traffic more rapidly than any other permanent type of bridge, because of the availability of plant-produced sections and the speed of erecting and finishing construction.