Comparison of Code Approaches for the SLS Design of GFRP Reinforced Concrete Flexural Members

Lluís Torres Llinàs; Cristina Barris Peña; Eva Oller Ibars; Marta Baena Muñoz

doi:10.33586/hya.2025.4130

Lluís Torres Llinàs Universitat de Girona http://orcid.org/0000-0002-7884-628X
Cristina Barris Peña Universitat de Girona http://orcid.org/0000-0002-5624-4202
Eva Oller Ibars Universitat Politècnica de Catalunya http://orcid.org/0000-0002-0845-3587
Marta Baena Muñoz Universitat de Girona http://orcid.org/0000-0001-8462-4942

DOI: https://doi.org/10.33586/hya.2025.4130

Keywords: Embedded FRP reinforcement, Flexural members, Design codes, Serviceability

Abstract

When Fibre Reinforced Polymer (FRP) bars are used as embedded reinforcement in concrete structures, serviceability behaviour often governs the design due to the lower modulus of elasticity of FRPs compared to conventional steel. While many design principles for steel-reinforced concrete remain applicable, the distinct mechanical and bond properties of FRPs require special consideration. In recent years, several international codes and guidelines have been updated or newly issued to address FRP reinforcement.

This paper presents a comparative analysis of the main aspects and provisions for serviceability limit state (SLS) design of Glass FRP (GFRP) reinforced concrete flexural members included in Eurocode 2 (2023), fib Model Code 2020 and ACI440.11-22. Stress limitation, crack width and deflections are carefully reviewed, and a design example is included, where the effects of different assumptions and limitations among codes are analysed and discussed.