RESEARCH AND NUMERICAL ANALYSIS ON FIRE-RESISTANCE PERFORMANCE OF SEPARATED COMPOSITE BEAMS WITH LAMINATED SLAB

In order to study the fire behavior of separated composite beams with laminated slabs, fire tests of four full-scale separated composite beams with laminated slabs under uniform loads were carried out. The considered influence factors included stud spacing, post-pouring layer thickness and overlap length between prefabricated slab and upper flange of steel beam. The temperature distribution of concrete along slab thickness, steel bar temperature, temperature field along the height of steel beam, bending stiffness and overall workability of composite slab and steel beam were studied. The temperature field and deformation behavior of the separated composite beams with laminated slabs under thermal-mechanical coupling were analyzed by ABAQUS. The results indicate that the bonding interface between the post-poured layer and the prefabricated floor is destroyed obviously during the heating process, but the loading capacity still exists. The overall bending stiffness of the composite beam decreases obviously due to the existence of the bonding interface and the joint of prefabricated slabs. Lap length has a significant influence on the deformation ability of composite beams with thermal-mechanical coupling effect. The experiment results are in good agreement with the numerical analysis results, so the validity and feasibility of the model are verified.