Standard aashto precast, prestressed concrete beams are widely used throughout the united states. The standard sections were developed in the 1950s taking into account the casting and handling techniques and the concrete mix design technology of the 1950s. In 1982, ina survey of bridges throughout the united states by the fhwa, it was determined that the aashto shapes were less efficient and less cost-effective than the bulb-tee shapes. Cost comparisons of an actual project are presented that was originally designed using type iv andtype iv modified beams but was redesigned and constructed using 54-and 63-in. Bulb-tee beams. The replacement of aashto beams with bulb-tee beams was permitted on a one-for-one replacement basis; therefore, the cost analysis reflects the cost differences of the beams inexactly the same load-span conditions. Comparative designs are shown and cost analyses of the designs are summarized, indicating total estimated cost savings of the bulb-tee solution over the standard aashto beam design. This paper appears in transportation research record no. 1319, Bridge and hydrology research 1991.
Samenvatting