Flexural behavior of precast prestressed slabs with embedded building service systems

Dry‐assembled precast concrete construction is rapidly spreading in many parts of the world due to the several advantages offered by industrialized construction. In order to speed up not only the assemblage of the structure, but also the full integrated building process, engineering systems (mechanical–electrical–plumbing) may be prefabricated and inserted within the thickness of each slab element, without having to lose further thickness on top or below them, later plugging and connecting the system network while assemblage is progressing. Relatively bulky plastic container boxes, pipes and derivations can be installed either mechanically within voided elements or embedded while casting solid slab elements. However, the presence of engineering systems embedded into the slab elements could modify their structural response mainly in flexure, due to the physical dimensions of boxes and pipes. This paper describes the outcome of experimental load tests on slender precast prestressed solid slabs with a realistic severe distribution of embedded engineering systems, both in terms of quantity and position along the element, with many of them located near midspan, though below the expected position of the neutral axis, simulating a credible limit case. A numerical analysis based on nonlinear section behavior shows good simulation of the flexural behavior experimentally observed, confirming low impact of embedded engineering systems compared to typical calculation assumptions for equivalent undisturbed members in flexure.