The "Professional recommendations for suspended floors with continuity boxes" published by the SEBTP in November 2009 define the design strips of these structures by integrating tolerances of use for continuity boxes from +/-15mm to +/-25mm.
The standard box calculations, which consider these tolerances, lead either to oversizing the standbys or practical impossibilities.
The specifically designed range of asymmetrical standbys optimise the load take-up of the link, particularly with respect to the flexing moment.
Benefits
With an equivalent load, fewer steel reinforcements to unfold than regular boxes
The asymmetry of the boxes avoids any risk of error in the fitting direction
Steel reinforcements to be unfolded according to the unfolding direction of the pre-slab hangers
Steel reinforcements are more easily accessible than in a regular box
The load take-up value is quantified thanks to abacuses
A more tolerant solution: the implantation precision has less incidence on the strength capacity that for a standard box
A compliance guarantee: the Predalbox is subject to an AFCAB certification request