GFRP Composite Culverts for Hydraulic and Agricultural Underpasses: Structural Behavior, Design, and Application

Corrugated steel-sheet culvert systems were extensively applied in the construction of hydraulic and agricultural highways underpasses from the 1980s until the beginning of the 21st century. Less than 30 years after being built, the level of corrosion in the steel sheets was found to be higher than expected, potentially compromising the structural safety and service life of these structures. In this context, it is urgent to develop durable solutions for both the rehabilitation of such underpasses and the construction of new ones. Recently, structural systems based on glass fiber–reinforced polymer (GFRP) culvert sections have been proposed as an answer to this issue and have already been used in a few rehabilitations, installed inside of existing steel culverts. However, doubts have been raised about the performance of this new solution, mainly due to the lack of consolidated knowledge about its structural behavior in this specific type of work. This paper presents an experimental and numerical investigation of the performance of a commercially available GFRP culvert system. The experimental program comprised coupon tests and full-scale flexural tests up to failure on GFRP culverts, with a 60-mm-thick wall, produced by filament winding, with a height of ∼2.15 m and a width of ∼3.40 m. Conventional finite-element (FE) models were developed with commercial FE packages to simulate the structural behavior of the GFRP culverts. Following validation, a design parametric analysis was carried out with those FE models, demonstrating that this structural solution is able to comply with serviceability and ultimate-limit states requirements. Finally, this paper presents a case study of the rehabilitation of an underpass originally built with corrugated steel sheets, using this new GFRP culvert. Overall, the results obtained in this study show the feasibility of applying GFRP culverts—both in new structures and when rehabilitating existing underpasses—and of using conventional FE tools in their design.