Parametric analysis of variables influencing the design of I-girder bridge decks made of high-performance fiber reinforced concrete

Abstract

Despite the good balance between notable mechanical properties and a reasonable cost, high-performance fiber reinforced concrete (HPFRC) is not widely employed in the construction of bridges. This work is part of a larger research addressed at exploring the potential of this material for replacing standard concrete in the construction sector. Specifically, this paper focuses on the use of HPFRC to build precast simply supported I-girders for road bridges. This work investigates the influence of several design variables on the material consumption to identify the key features that can lead to possible material savings. The variables, explored through a parametric analysis, are: (i) the concrete class (C80/95, C100/115, and C120/140); (ii) the number of beams to form the deck (from 3 to 5); (iii) the girder span-to-depth ratio (17, 20, and 23); (iv) the bridge span (L) (20, 40 and 60 m). One specific case of study is described in detail, and then the same procedure is applied to all the case studies. In addition, the effect of different hypotheses and formulations for the bending and shear verifications are analyzed. The results shed light on the relevance that these variables play in the final solution and how they affect the dimensioning of these elements. As main finding, this work proves that the use of HPFRC represent a material-efficient solution for slender and long-span precast I-girders.