Assessment of joint temperature design in EN 1993-1-2:2024 through full-scale fire tests

Accurate prediction of joint temperatures is critical for the structural design of steel-framed structures under fire. The new Eurocode EN 1993–1–2:2024 permits joint temperatures to be taken as equal to those of the connected beams, but the accuracy of this design recommendation has not been fully verified in published articles. This study assesses the provision through collected temperature data from multiple full-scale compartment fire tests, covering both protected and unprotected joints. The collected data covers the fuel load energy density from 700 MJ / m 2 to 1350 MJ / m 2 , and the ventilation factor from 0.04 m 0.5 to 0.06 m 0.5 . The results show that EN 1993–1–2:2024 consistently overestimates joint temperatures for both protected and unprotected conditions. Based on these findings, a simplified design method is proposed, adopting 0.8 times mid-span beam temperature for protected joints and 0.9 times mid-span beam temperature for unprotected joints. In comparison with the experimental data, the recommended approach provides a more realistic yet conservative estimate, offering a rational balance between safety and efficiency.