Why Precast Concrete Outperforms On Bridge Construction

In the United States, there are more than 617,000 bridges, half of which are older than 50 years old. Roughly 7.5% of bridges are considered to be in poor or damaged condition. The use of precast concrete, however, improves the quality of bridges, while remaining inexpensive. The use of precast originated in the early fifties to late sixties, and has been in use ever since. 

The Different Components Of Bridges


Flat Slabs
Coming in at anywhere from six to ten feet, flat slabs are flat beams that span across the length of smaller bridges, typically with spans of 25 to 45 feet between supports.
Adjacent Boxes
These structures span the length of medium sized bridges, typically at a shallower depth superstructure system. 
Pretensioned Beams
Being the most common element found in precast bridges today, Pretensioned Beams span the length of medium to long bridges. These are the types found in highway bridges 
Extending Span Ranges And Span Girders
These structures extend along the length of the bridge, reaching lengths of up to 325 feet in length.
Curved Girders
While controversial, these structures have yet to fail. These can span up to 300 ft and have depths of anywhere from 72 to 132 inches. 

Precast End Bents
These can be used in both large and small structures.
Piles And Pile Bent Caps
These are commonly used to accelerate bridge construction projects.
Water Line Pile Caps With A CIP Column
Accelerate construction and simplify dewatering operations. 
Precast Columns
These come in a variety of shapes depending on the precast producers or in order to meet the project's needs. 
Pavement Slabs
These offer a fast and durable way of replacing and repairing roadways and bridges. They are usually made to fix the size needed and can extend to all lanes. 
Sound Walls/Noise Barriers
These are designed to meet noise requirements in the area and are made to reflect sound when needed.  

What Is Precast

Precast is the material that is used to make up the various structures found throughout the United States including bridges.  It brings numerous benefits to both transportation clients and the communities that surround projects made with precast. 

Accelerated Construction/Use of ABC techniques
Precast provides a cheaper and faster way of making bridges opposed to other methods. Precast can be made into whatever is in need for the current project and takes less time to utilize. 

Less Workers/Safer for Workers
Precast can also reduce the cost of construction by needing less people and making it safer and easier for the workers involved to do what they need to do. 

Less Long Term Maintenance
Precast structures are built to last, so they don’t require regular maintenance. Once they have been set in place, the bridge can go a really long time without the need of repair. 

Produced Offsite in Quality Controlled Environment
The parts used for construction are produced offsite, meaning the part just has to be put in place when needed.  

Case Studies

U.S. Highway 12 Bridge

Major reconstruction was underway for this bridge and the crew was tasked to place 80 beams. They used precast beams and were able to do it in a little over one month. 

U.S. 10 Bridge

This bridge was being reconstructed over plum creek. With all the precast pieces available, the bridge was set in one day and was open and available for use in one month.

IDOT Bridge Reconstruction

This was IDOT’s first accelerated bridge construction project. In just 72 hours, the bridge was taken down and rebuilt. 

Precast is a very useful component in the bridge construction industry. Time and time again it has proven to be fast and cost effective. Precast makes for the perfect solution to the need for fast and effective bridge construction. Precast also eliminates the need for a lot of labor and can be made offsite, leading to rapidly accelerated construction.