The University of Maine in the US has unveiled a system for building highway bridges in just 72 hours using composite material girders and precast concrete deck panels.
The lightweight, stackable girders are twice as strong as steel and concrete girders, and the system can be erected with common rental cranes,
As well as being a logistical breakthrough, up to four bridges can be transported on a single flatbed truck, researchers said the system is durable and easily maintained: girders are designed to last 100 years and the precast deck can be easily replaced.
The system can be used for short- to medium-span highway and pedestrian bridges, and by the military, the university said. The design allows for up to 80-foot unsupported spans.
Last month a bridge girder was strength-tested in the laboratory using hydraulic equipment that simulated the heaviest highway truck loads.
The test proved design modelling predictions and showed the bridge system can withstand the loading specified in the American Association of State Highway and Transportation Officials (AASHTO) Bridge Design Specifications.