Composite Hollowcore Analysis can be achieved using any 2D structural analysis program. The centerline of the hollowcore slab and the topping concrete are modeled as frame elements that are connected together using rigid arms. Horizontal (shear) and vertical (peel) springs with zero length are to connect the rigid arms to the topping slab. For hollowcore slabs with machine-cast surface and considering elastic analysis, the shear stiffness was found to range between 2 and 8 (N/mm)/mm², while the peel stiffness was found to be constant at 1.5 (N/mm)/mm². These stiffness values are based on experiments for hollowcore slabs from two manufacturers. The exact values must be determined for your specific project.
Such modeling technique is adequate for serviceability checks (stresses, cracking, and deflection). However for ultimate limit state, advanced non-linear modeling, which accounts for construction stages, and nonlinear behaviour of concrete, prestressing steel, as well as the shear and peel springs, is needed.
For more information, please refer to:
Adawi A, Youssef MA, Meshaly ME, 2016, “Finite Element Modeling of the Composite Action between Hollowcore Slabs and the Topping Concrete“, Engineering Structures, 124: 302-315.
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