Accelerated Bridge Construction

The Accelerated Bridge Construction (ABC) is a fundamental change in the approach employed in planning of projects and the acquisition of materials, in a manner that is safe and cost-effective to reduce the time required for onsite construction when building new bridges or rehabilitating and replacing existing bridges. 

Photo courtesy of PCI Gulf South

Bridge Stats in the US

According to the Federal Highway Association (FHWA) there are over 600,000 bridges in the US. Approximately one out of four of the nation’s 600,000 bridges need total replacement, repair, or rehabilitation. About 8% of these 600,000 bridges are structurally deficient and there is a need for urgent repairs.

What is Accelerated Bridge Construction or ABC

For over twenty years now the construction industry has shifted into using the accelerated bridge construction approach, which involves using prefabricated road and bridges elements. Once prefabrication of elements is completed offsite, they can be slid and moved into place quickly to reduce inconvenience to the public and also enhance the safety of construction workers. The prefabricated bridges components undergo quality controls before they are transported to the site for assemblage. The use of accelerated bridge construction is now employed all over the world for the construction of malls, houses, and for construction of roads and bridges because of all the benefits associated with it which include, improvement of workers’ safety, the overall quality and reduction of inconvenience to the general public. From the perspective of the client, accelerated bridge construction may require a change in how projects are approached and justified.

A very good advantage of employing ABC is to reduce mobility impacts or better still reduce traffic flow, this is because the flow of transportation network and the general safety of road users are linked directly to the impact of the activities associated with onsite construction. Onsite construction has been associated with significant social impacts on safety and mobility. In several cases, the direct and indirect costs of traffic detours which may arise from the loss of a bridge during construction are sometimes greater than the actual cost of constructing the structure itself. Although, other good reasons to use ABC have to do with site constructability issues. Most times, the ABC approach can provide solutions that are economical and more practical compared to solutions provided by conventional construction methods which are associated with costly use of temporary structure, long detours, long construction duration, and the use of remote site locations during construction.

Learn more about how off-site construction methods, like those used for ABC projects, improve time spent and safety on construction sites. 

Precast and ABC Methods

Precast are great choice for accelerated bridge construction due to their accelerated construction, versatility, resiliency, and their high degree of quality. Precast are usually constructed off site , they can be easily installed on sites, and they require less future maintenance due to the quality control the pass through off site. 

Types of Precast Components Used with ABC

Some of the precast components used in accelerated bridge construction include those below. Click on each to learn more about each component.



Northeast Bulbtee (NEBT)
Resources on Northeast Bulbtee and Northeast Deck Bulb Tee



Northeast Extreme Tee (NEXT) Beam
Resources on Northeast Extreme Tee (NEXT) Beam



Bridge Deck Panels
Resources for partial depth deck panels and full thickness deck panels

ABC Case Studies



Bath Viaduct
Bath, NE


Bridge deadline was 220 days and was opened 1 month early using ABC methods



Route 73 Rochester Bridges 15 & 16
Rochester, VT


Bridge 15 reopened in 72 hours and Bridge 16 reopened in 52 hours using ABC methods



Route 8 Bridge Deck Replacement
New Hartford, NY


Bridge was completely removed and replaced in 95 hours

Conclusion

Accelerated bridge construction involves the construction of bridge component offsite and transporting the component onsite for installation. Most of the components used in ABC are precast which are good quality materials that can be easily installed when they are transported to the construction site. The use of precast in ABC has helped to reduce many of the major problems encountered using conventional bridge construction.