Experimental and numerical investigation on the flexural behavior of a novel composite slab with a joint

Composite slab has extensive application in building industrialization. In this study, a novel composite slab with a joint was proposed, where the precast planks with bent-up rebar are only partially prefabricated along the thickness direction at the joint for cast-in-site pouring of concrete, and the rest is fully prefabricated in the factory. The flexural performance of the composite slab was compared with that of a traditional cast-in-site slab with the same geometric dimensions through four-point bending test. The results demonstrate that the bending performance of the composite slab, including cracking load, yield load, and ultimate load, is basically consistent with that of the cast-in-site slab, and can meet the engineering requirements. Based on experimental results, numerical research was conducted on the composite slabs. The effects of slab thickness, diameter of steel bar, concrete strength of precast plank, and slab span on the flexural behavior of composite slab were investigated. The numerical results show that the cracking load, yield load, and load corresponding to the deflection limit of the specimen increase with the increase in slab thickness and decrease with the increase in slab span. Increasing the steel bar diameter can increase the load corresponding to the deflection limit and yield load, while the effect on the cracking load is almost negligible. The concrete strength of precast plank has no significant effect on the flexural behavior of the composite slab.