Abstract: To ensure the fire safety of timber hybrid structures, a full-scale fire resistance test was conducted on horizontally bonded laminated timber (HBLT) floor slabs following the standard fire heating curve. The test results showed that the fire resistance rating of the HBLT floor slab was not less than 1.50 h. No collapse occurred to the test specimen after fire exposure, with a maximum mid-span deflection of 7 mm, indicating no loss of load-bearing capacity; no flame appeared on the unexposed surface, maintaining the integrity of the specimen; the average temperature of the unexposed surface rose by 26 ℃, and the maximum temperature at a certain point on the unexposed surface increased by 68 ℃, showing no loss of thermal insulation performance. In addition, the measured char layer thickness of the HBLT floor slab was within the design safety range. The above results demonstrate that the HBLT floor slab has excellent fire resistance under fire conditions, providing experimental evidence for the fire protection design of timber hybrid structures.

Key words: horizontally bonded laminated timber floor slab（HBLT）, standard fire, fire resistance rating, char layer thickness