Competitiveness Of Composite Beams

Abstract

The paper presents the economical comparison between composite I-beams and reinforced ribbed slabs. The comparison has been made for simply supported and continuous beams for different spans and different loads. As spans and loads have been proposed to be sequentially increased step by step, a large number of different structural alternatives have been defined for the calculation. Many different structural steel grades, reinforcing steel grades and concrete strength classes have been considered for the design. Beams have been designed for the ultimate limit state and for the serviceability limit state at all four different classes of cross-sections (from Class 1 to Class 4). In the addition, plastic analysis and/or elastic analysis, rolled standard sections and/or welded steel sections, shear connections, creep, shrinkage, fire resistance, positive and negative bending moments and lateral torsion at the continuous beams have made the problem highly comprehensive. Self manufacturing (material and labour) costs have been calculated for all design alternatives. Further, the comparison between costs of the obtained results has been made for all defined spans. In this way, we found the competitive spans of composite I-beams for different loads for simply supported and continuous girders. The analysis was performed in accordance with Eurocode 2 for ribbed slabs and Eurocode 4 with Eurocode 3 for composite beams.