Precast Prestressed Concrete Bridge Girders with Unbonded Tendons.

The design, manufacture and erection of a precast prestressed concrete bridge girder weighing 100 t, with unbonded tendons, are described. The construction firm entrusted with these operations was Betonwerk Kotthaus, Eschweiler, who worked in collaboration with the client to produce a design which, based on the latest state of the art and on concepts introduced under a new code of practice, would achieve optimum durability of the girder under extreme service conditions. The form of construction adopted for the project satisfied practically all requirements as to technical performance, completion time and economy.