Prestressed Concrete Beams Intermixed with Steel Beams for Bridge Widening

摘要

Many of the bridges built in the past were designed and constructed with steel plate beams or steel wide-flanged sections which support the roadway. In the widening of certain bridges, the option to support the additional width with prestressed concrete beams is desirable. However, it is possible that the use of prestressed concrete beams in combination with steel beams in the same span can introduce problem areas caused by time-dependent, thermal, stiffness, and other effects. The investigation here reported consisted of three main parts: the adaptation of a commercially available computer to a span having a combination of steel beams and prestressed concrete beams; the field testing of a typical span as a means of evaluating the computer program; and the use of the computer program to identify potential problem areas. The results of the investigation indicated that the computer program could be used to predict accurately the behavior of a span having intermixed steel and prestressed concrete beams and that there may in inherent problems associated with the use of prestressed concrete beams and steel beams in the same span when supporting a monolithic concrete slab.