Experimental study on flexural behavior of a novel variable-grade prefabricated concrete slab with surrounding composited

This paper investigates a novel variable-grade prefabricated concrete (PC) slab with surrounding composited which has high prefabrication rate, sufficient installation rigidity, high on-site construction efficiency, and good overall working performance. To improve the crack-resistance performance of the transverse superposed surface and the overall working performance of the proposed novel PC slab, we optimize the position of variable-grade and arrange it at the location where the bending moment is close to zero. We perform comparatively bending tests on three two-span full-scale slab strips that include boundary and intermediate beam-slab joints to systematically investigate the flexural behavior of the proposed novel slab. The load versus deflection relationship, failure mode, distribution of cracks, development law of crack width and development of steel strain are comparatively studied. The test results confirm that the flexural behavior of the proposed novel PC slabs are similar and slightly better than that of the cast-in-place slab in general. No crack or slippage appears at the interface between the precast panel and the post- pouring concrete. The connection method of L-shaped anchorage rebars lap splicing in this study is cost-effective, efficient, and reliable. Furthermore, we establish a finite element model and perform a parametric investigation on the proposed novel PC slab. Parametric simulations conclude that the increase of the strength of post-pouring concrete and post-pouring layer thickness can improve the bearing capacity of the proposed novel PC slabs.