FRP reinforced-concrete slabs: a comparative design study

Durability of concrete structures represents a major challenge today for both existing and new structures. Fibre-reinforced polymer (FRP) composite rebar offers a highly durable alternative to steel rebar. Research on the use of FRP rebar has been conducted over the past 40 years; however, its widespread application is yet to occur. This paper investigates the use of FRP as reinforcement, in particular the application to slab elements and associated performance at serviceability and ultimate limit state. Existing design guidance such as the ACI and CSA standards are reviewed and a number of slab designs with dimensions common in practice are undertaken. A third approach that follows the Eurocode design philosophy is also reviewed. The design of the different slab forms is assessed according to these codes, and results compared with the behaviour predicted by non-linear finite-element analysis. The relative costs of each resulting slab design are also discussed. The findings highlight differences in the relative accuracy of the different code recommendations and indicate the need for further research to exclude potentially non-conservative design. The work presented is intended to provide a contextual comparison of existing design approaches, which will be useful to practitioners involved in design of concrete structures with FRP rebar.