Study on shear performance of notched connections for glulam-concrete composite beams under fire

Shear connection guarantees that the timber beam and concrete slab of a composite beam interact effectively. Shear connection performance markedly affects the fire resistance of timber-concrete composite beams. Shear connection experiments under fire are uncommon in comparison to those conducted at ambient temperature, and there have been few previous investigations on the shear performance of notched connections under fire. Six specimens were sheared at ambient temperature and ten specimens were sheared at elevated temperature in this study to determine the shear behavior of notched connections exposed to ISO fire. The length of the notch connection and the duration of fire exposure are two factors that may influence the shear behavior of the connections. With the increase of fire time, the shear bearing capacity and slip modulus of notched connections decreased. As notch length increased from 150 mm to 250 mm, the failure modes of shear specimens under fire changed from shear failure of concrete in the notch to compression failure of timber near the notch. Experimental results and finite element thermal analysis results were used to establish an analytical model for the shear bearing capacity of notched connections for glulam-concrete beams under ISO fire exposure.