Research summary · Experimental and numerical study
Fire resistance of protected glued laminated timber columns: Geometry, load and cladding effect. Structures, 84 (2026), 110981. Published online on 23 December 2025.
Authors: Paulo A. G. Piloto; Manuel D. Lorenzo; Ana B. Ramos-Gavilán; Javier Sánchez-Haro; Loïc Lannou; Abdelhamid Bouchaïr.
Read the paper and DOI: 10.1016/j.istruc.2025.110981
Research question and method
How do geometry, load and gypsum cladding affect the fire resistance of glued laminated timber columns? The study combines three tests, a three-dimensional finite element model and a parametric analysis.
Main finding
In the numerical scenarios studied for GL24h columns measuring 80 × 100 mm and 1.2 m long, increasing the protection from one to two 12.5 mm gypsum layers increased fire resistance time by approximately 70–95%, depending on the load. The response also depends on slenderness and timber strength class.
Scope and limitations
These values apply to the analysed configurations and are not a general design guarantee. The experimental campaign covers one cross-section, two load levels and two levels of protection; the other scenarios are explored through simulation.
Collaboration and participation
The work was carried out with Paulo A. G. Piloto of the Polytechnic Institute of Bragança (IPB) and the coauthor team. The contribution statement credits Manuel D. Lorenzo with conceptualization, investigation, and manuscript review and editing.
Related links
Original science communication summary of the cited paper. Reviewed on 13 October 2026.