Structural optimization of RC composite girders in pre-fabricated buildings

This paper presents cost optimization analysis of reinforced concrete composite girders in RC
pre-fabricated buildings designed according to the Egyptian Code of Practice (ECP 203-2017).
The adopted objective function was to minimize the total cost of the RC pre-fabricated building
including the cost of composite girders, columns and foundations considering the cost of the
materials and labor for reinforcement, concrete and formwork. The structure is modeled and
analyzed using a Microsoft Excel- 2013 spreadsheet. The optimization process was performed
at three different levels. In the first level, optimum column arrangement was attained while the
optimum dimensions for all RC elements of the selected structural plan of the pre-fabricated
buildings were studied in the second level. In the third level, a comprehensive study was
conducted in order to determine the optimum dimensions and reinforcement of RC composite
girders by Generalized Reduced Gradient (GRG) method. Finally, the cost improvement of three
buildings of composite concrete is demonstrated, and the results of the optimum and traditional
design procedures are compared