Concrete Bridge Design & Construction series

A new series from the Concrete Bridge Development Group (CBDG). This article demonstrates the benefits of using concrete.

This second article from the Concrete Bridge Development Group’s technical committee, examines the initial parameters that might determine the best layout for a new bridge.

This article examines the prestressing for a concrete bridge. Prestressing enhances the capacity of a member that is weak in tension, but strong in compression. It effectively creates a new material that is strong in tension. A prestressed bridge has much less steel to be handled, which reduces congestion, leading to easier and quicker concrete placing.

This article examines the selection process for the most suitable type of concrete bridge. The general parameters of the scheme such as typical spans, overall deck area, clearance requirements, alignment and the overall aesthetic will start to suggest which type of bridge deck and construction methods might be appropriate.

In this article, the various types of formwork and falsework needed to construct a concrete bridge are examined. The choice of bridge type depends not only on the general parameters of the scheme (such as typical spans, overall deck area, clearance requirements, alignment and the overall aesthetic), but also on the particular and local parameters of the site, many of which are related to construction.

In situ options tend to be used on projects where the speed of construction is not critical, or where the lower costs of the in situ works justify a slightly longer programme.

This month’s article from the CBDG’s Technical Committee examines the construction methods for the six basic types of precast concrete bridge.

This article examines the various methods for the design and construction of concrete arches, frames, tunnels and jacked boxes, which cover the whole range of bridges from the smallest culverts to the largest concrete spans in the world.

The various high performance concretes that might be used for concrete bridges, to make them either quicker and easier to build, or more economic are discussed. The advantages of high strength, lightweight, fibre reinforced and self-compacting concretes are described, together with the use of new materials that can replace steel for both reinforcement and prestressing.

This article examines the detailing that is particular to a concrete bridge. All details need to consider buildability, durability and maintainability, as well as safety and aesthetic issues.

The penultimate article in this series examines the special types of concrete bridge. Concrete cable-stayed, extradosed and stressed ribbon bridges are all described here, together with the special features of concrete footbridges and railway bridges.

The final article in this series examines the long-term management of concrete bridges. The inspection and assessment of a bridge over its entire life, the maintenance requirements and possible strengthening to upgrade the bridge to a new load configuration or revised layout are discussed.