Optimum design of precast prestressed concrete bridge girders

This study covers the determination of the optimum one of TYPE V and TYPE VI precast prestressed bridge girders, which are considered to be suitable for very long spans among the standard beams with 6 different cross sections recommended by AASHTO for using in the bridge superstructure, and to perform analysis in accordance with design rules in order to determine which one could be used in a bridge with a width of 11 meters, a span of 40 meters and 2 lanes more effectively in terms of both cost and performance by comparing the analysis results of these two types of girders. Detailed analysis of TYPE V girder was carried out and the obtained results were prepared in summary tables and charts together with those of TYPE VI girder. In the detailed analysis of the TYPE V girder, the prestress losses occurring in the pre-tensioning steel strands in the pre-tensioning and service phases were calculated, and the stresses developing in the sections under 4 different loading cases were checked with the allowable stresses recommended by AASHTO. Shear and bending capacity and deflection calculations of TYPE V girder were also made in detail. Comparative cost analyses were made by calculating the quantity of concrete, rebar and pre-tensioning strands of TYPE V and TYPE VI girders and multiplying them with the current unit prices taken from the real market.