Crack-Width-Based Sectional Analysis of Fiber-Reinforced Concrete Applied to the Structural Design of the Slab of a Fly-Over Bridge

Abstract

The use of fibers in reinforced concrete offers an opportunity to optimize the structural design while increasing durability. A sectional analysis that considers the stress-crack-width relation obtained for steel fiber–reinforced concrete (SFRC) and polyolefin fiber–reinforced concrete (PFRC) was used for the structural design of two fly-over bridge typologies. Moment-curvature diagrams were produced using an iterative process that took into account not only the strain conditions but also the crack appearance and evolution. The contribution of fibers to the shear resistance was calculated following the formulation proposed by Model Code 2010. The results obtained showed that the contribution of the fibers enabled a reduction in flexural reinforcement of up to 40% and 30% in the cases of SFRC and PFRC respectively. In relation to shear stirrups, notable reductions could be achieved for both SFRC and PFRC but could be greater in the case of PFRC. Lastly, the economic impact of the use of fibers in the construction costs was quantified.