The application of composites (FRP) in military bridges

The needs of expeditionary forces involve the use of light-weight, short-span bridges so that their transport by air would be possible. A project which is currently developed in USA aims at the elaboration of a Composite Army Bridge (CAB) assault bridge and a Modular Composite Bridge – MCB logistic bridge. In 2004 CAB successfully underwent fatigue tests. A 14 m-long, all-composite treadway bridge span was loaded by using an MLC 100 vehicle and it withstood 20 000 load cycles. The MCB will be constructed by7 m of box modules and a 6.5 m access ramp. A 26 m-long and 4 m-wide bridge span is to provide the traffic ability of MLC 65. Furthermore, works on a 10 m-long, MLC 30 composite bridge are also developed in Canada too. The paper also presents the American concept of employing a deployable bridge system by utilising a composite structure. In order to formwork and reinforce the plate, fibre reinforced polyester composites (FRP) were used. The girder construction is made of aluminium pipes forming diamond truss with curved bottom chord. After they are integrated in the structure, the top chord nodes are connected through deck plate cast in-situ. The tests indicated that there exists the possibility of using polymer composites in military bridge construction and mobile structures of composite bridges.