65 / 2022-04-02 16:32:31

Experimental study on seismic performance of composite beam with laminated slabs using comprehensive anti-cracking technology

Composite beam with laminated slabs,Uplift-restricted and slip-permitted connectors,Experimental investigation,Seismic performance,Anti-cracking performance

Composite beam with laminated slabs is a kind of composite beam which is suitable for long-span, heavy-load and assembly construction, but the concrete slabs are easy to crack in tension in positive moment. In order to improve the anti-cracking performance of concrete slabs, comprehensive anti-crack measures were adopted, including uplift-restricted and slip-permitted perforated steel plate connectors and cast-in-place layer of fiber anti-cracking high performance concrete. Five composite beam-steel column joints were tested by quasi-static test. The analysis parameters included the shear connectors type, cast-in-place concrete material and reinforcement strength. The study results indicate that: (1) the anti-cracking performance of composite beams can be improved by adopting the uplift-restricted and slip-permitted perforated steel plate connectors and the fiber anti-cracking high-performance concrete in cast-in-place layer, the comprehensive use of the two anti-cracking measures has better effect, while the strength of steel bars in cast-in-place layer has less influence on the anti-cracking performance of composite beams; (2) the ultimate bending capacity of composite beams in positive moment is less affected by the concrete material of cast-in-place layer and the strength of steel bars; (3) the bending stiffness of composite beams can be improved by using perforated steel plate connectors; (4) composite beams with perforated steel plate connectors have good ductility and seismic performance, and the seismic performance of composite beams can be further improved when fiber anti-cracking high-performance concrete is used in the cast-in-place layer, but the strength grade of steel bars in the cast-in-place layer has little effect on the seismic performance.