ABSTRACT
During the last decades the use of fiber reinforced concrete (FRC) has been increasing and extending to different areas where structural responsibility was required, being the latest research focused on suspended slabs only made of FRC. This could suggest that more fields of concrete structures could benefit from this material, including bridges. This paper presents the research about a bridge design considering FRC. An assessment on how the material can influence both design strength and expected service response is given (sectional strength and crack width). The existing Line 2 Metrorrey’s viaduct is used as reference to perform the structural analysis and design, where both conventional and fiber reinforced concretes are evaluated. The bridge is modeled and analyzed by means of standard numerical analysis and current code regulations are used to obtain preliminary ultimate and serviceability design loads. The assessment of the bridge is mainly based on the verification of the bottom slab of the girder, as it is one of the major elements where FRC can provide an increase in the element performance (compared to a conventional solution). Considering the Metrorrey transverse prestressing, FRC can effectively replace the required reinforcement to fulfill ultimate load case while the prestress itself provides decompression in serviceability load levels. This is possible as the internal load levels require for little amount of rebar reinforcement, which can be structurally comparable to FRC mechanical contribution, similarly to previous applications of the material, such as suspended slabs. Due to higher internal forces, in terms of ULS load-bearing capacity the transversal cross-section near the pier do not benefit from FRC as much as the mid-span slab although its minimum serviceability reinforcement can be reduced up to 56%, as the contribution of FRC to reduce the crack width is considerable. This could turn FRC into an attractive solution for tight crack requirements as durability demand increases.
