The quality of structural
design and the resulting quality of the structure’s performance depends on the
level of knowledge of structural behaviour. The structural behaviour of RC
waffle floor slabs and composite waffle slabs has been theoretically analysed
and verified in a wide range of experiments. The results of the tests,
supported by theoretical conclusions, have confirmed significantly better
structural properties of the composite waffle slabs than the assumptions
commonly considered in analysis models. Primary theoretical assumptions of high
torsional rigidity of waffle slabs have been proven. The ribs of the tested
specimens were however not reinforced with shear and torsional reinforcement.
This paper presents some generalised conclusions as a basis for the formulation
of principles and procedures of an optimised design of composite waffle slab
structures.