A modular precast concrete system has been developed, which consists of relatively light 2.5m long shell units that are cast off site and can easily be transported to the required location. On site the units are assembled, stressed together and in situ concrete placed. The combined units are positioned using launching or lifting technology, depending on the site characteristics.
The system provides designers with a concrete solution for medium span bridges that can be used in the majority of locations. Modular precast concrete bridges gives details of the concept, structural details for spans up to 50m and deck widths up to 1m and reviews the various construction options (lifting complete spans, incremental launching, self-propelled transporters, gantries). Various case studies are included that compare the costs of the new system with those of more conventional approaches.
The Concrete Bridge Development Group Technical Guide 11, Modular precast concrete bridges, 2009, describes the system.