Fire Behaviour of GFRP Composite Panels for Rehabilitation of Building Floors – FireFloor

FundingPortuguese national funding agency for science, research and technology (FCT)

Reference – PTDC/ECI-EGC/30611/2017

Budget – €227.449,20

Period – 10/2018 to 10/2022

Principal Investigator – Dr. João Pedro Firmo

CORE Group members involved – Prof. João Ramôa Correia; Dr. Mário Garrido; Eng. Pietro Mazzuca, Eng. Eloísa Castilho, Dr. António Duarte, Dr. Mário Sá, Dr. Mário Arruda


The replacement of degraded floors (namely timber ones) with traditional materials introduces significant dead loads in constructions, increasing their seismic vulnerability. GFRP materials present several advantages, namely their high mechanical performance, lightness, durability and increasingly competitive costs. Although GFRP panels have been successfully used in a wide variety of structural applications, there are well-founded concerns about their fire behaviour. This issue is yet to be addressed in a comprehensive manner and has hampered their use in building floors, where strict fire requirements have to be respected.

In this project the fire behaviour of GFRP composite panels will be assessed; the influence of different core materials and GFRP architectures on their fire reaction and fire resistance properties will be evaluated. The effectiveness of different passive fire protection systems will be assessed to enable their structural use in buildings. This will imply coupling a comprehensive experimental study with the development of supporting numerical modelling tools.

The experimental study will include (i) specific tests to evaluate the thermophysical properties of all materials; (ii) small-scale mechanical tests (tension, compression, shear and flexure) at elevated temperatures; (iii) fire reaction tests and (iv) full-scale fire resistance tests on loaded GFRP panels insulated with different fire protection systems. The numerical modelling will comprise the incorporation of the constitutive relations as a function of temperature of all materials and the assessment of appropriate failure criteria; after validation with the experimental results, the models will be used to optimize the geometry of the panels and the fire protection systems.

This project will provide: (i) in-depth understanding of the fire behaviour of GFRP panels, (ii) tailored fire protection systems that will enable extending their safe use in building floors; (iii) numerical models to simulate their fire response, and (iv) a manual for fire protection design and technical recommendations. Collaboration with manufacturers and associated industry will also allow for the development of technical and industrial capacity in this arising area of structural rehabilitation.

PhD Theses

Pietro Mazzuca, “Fire Behaviour of GFRP Sandwich Panels for Rehabilitation of Builing Floors”, orientador; University of Calabria/IST-ULisboa (Joint-Degree), PhD Thesis in Civil Engineering. September 2022, (supervisors: J. P. Firmo, J. R. Correia, L. Ombres).

Bruno Aguirre Tessaro, “Thermo-Mechanical Structural Modelling of GFRP Profiles Subjected to Fire”, Engenharia Computacional, IST/U-Lisboa École Centrale de Nantes (Joint-Degree), Supervisors: C. Tiago; J.R. Correia and L. Stainier (on-going).

Eloísa Maria Castilho dos Santos, ” Temperature-dependent behaviour and viscoelasticity of fibre polymer composites and polymeric foams used in sandwich panels”, PhD in Civil Engineering, Instituto Superior Técnico of the University of Lisbon, Supervisors: J. P. Firmo, J. R. Correia, M. Garrido (on-going).


Recent International Journal Papers:

P. Mazzuca, J.P. Firmo, J.R. Correia, E. Castilho, Mechanical behaviour in shear and compression at elevated temperature of polyethylene terephthalate (PET) foam, Journal of Building Engineering, Vol. 42, 102526, 2021. DOI: 10.1016/j.jobe.2021.102526

P. Mazzuca, J.P. Firmo, J.R. Correia, M. Garrido, “Mechanical behaviour in shear and compression of polyurethane foam at elevated temperature”; Journal of Sandwich Structures & Material, pp. 1-21, 2021.DOI: 10.1177/10996362211050919

M. Proença, M. Garrido, J. R. Correia, M. G. Gomes, Fire resistance behaviour of GFRP-polyurethane composite sandwich panels for building floors, Composites Part B, Vol. 224, 2021. DOI: 10.1016/j.compositesb.2021.109171

P. Mazzuca, J.P. Firmo, J.R. Correia, E. Castilho, Influence of elevated temperatures on the mechanical properties of glass fibre reinforced polymer laminates produced by vacuum infusion, Construction and Building Materials, Vol. 345, 2022. DOI: 10.1016/j.conbuildmat.2022.128340