Experimental Investigation on Out-of-Plane Flexural and Shear Performance of Half Steel-Concrete Slabs

Half steel-concrete slabs have been used in nuclear power plants and high-rise buildings as floor and roof panels. In order to study the failure mechanism, fifteen one-way Half-SC slabs with different steel faceplate thicknesses, stud numbers, shear span ratios, and volume tie bar ratios were tested under three-point or four-point loading. Mid-span deflections, strains of steel faceplate and concrete, and slippage between concrete and steel faceplate were measured. The result shows that Half-SC slabs exhibited four types of failure mode: flexure, shear, balanced, and interface slippage failure. Flexural failure was initiated by the tensile yield of the steel plate and followed by concrete crushing, which was similar to reinforced concrete slabs. In shear failure, when the shear span ratio is greater than 1.5, the steel plate in the shear-compression zone would achieve yield strength, and the ultimate failure is caused by the concrete crushing between the loading point and the support or by excessive plastic deformation of steel faceplate. This is significantly different from that of the reinforced concrete slabs. The increases in the volume tie bar ratio could postpone the occurrence of shear failure and even converted failure mode to flexural failure. The flexural strength was calculated. Based on a tie-arch model, the calculation equation of shear strength was proposed. The calculated results agree well with the experimental data. Besides, these formulas were a good predictor of the transition between bending failure and shear failure with the shear span ratio.