The Unidome technology cosists of a construction method,
a design concept and the corresponding building products to realize the Unidome construction method.
This construction method is a material-efficient lightweight construction method in which material is eliminated
where it has only a negligible
load-bearing function.
The Unidome design concept is a methodology developed over decades
to be able to calculate the resulting cavity structures simply and reliably
by using the factor method to apply the conventional
and internationally recognized design principles
in reinforced concrete construction.
The Unidome construction products are concrete formers
developed and tested for their respective applications to create safe,
economical and sustainable concrete structures.
Unidome is an international brand and holds international
patents and approvals.
PLANNING AND DESIGN
The design concept for the biaxial voided slabs developed by Dr. Pfeffer, based on the results of research carried out specifically on this subject, is now considered to be the internationally recognized state of the art. The resulting parameters for the design of the voided slabs are easy to handle, so that the design can be carried out by any structural engineer in the same way as the design of a solid flat concrete slab.
How to design a slab with Unidome shapers?
- Estimation of slab thickness and first run of FE- calculation:
Analogous to the design of a solid flat slab, a first slab rough slab thickness to start the FR – based computation is determined. Before running the calculation , a reduce dead load has to be taken into consideration on the impact-side (determineted by the weight of the solid slab reduced by the load reduction trough the concrete shapers /m2). At the same time, the bending stiffness of the cross section needs to be manipulated according to the Unidome tables. By applying both parametars to the entire slab, we assume 100% of the slab are covered with concrete shapers.
2.Verification of distribution of shear forces:
In order to guarantee the admired performance and in order to adapt the technology entirely, the distribution of shear forces has to be counterchecked. Unidome concrete shapers are admissible in all areas where the governing shear forces are less than 50% of the shear resistance of the solid flat slab.
fshear Factor for the consideration of the reduced shear resistance of a slab with cavities, to be taken from Data sheet
Concrete shapers have to be removed again in all areas providing higher shear forces, which happens to benear suppotings, providing that the initial assumption (concrete shapers covering the entire slab) is proven wrong. By those means partial solid areas are now established by re-manipulation dead load and stiffness back to solid properties.
3.Final verification:
Now that the slab design precisely provides separate for both areas (concrete shaper area and solid area) run a final calculation to check whether all results remained within the boundary condition.
Shear punching areas of columns/wall endings must not interfere with the Unidome areas. Also keep the minimum solid distance to the slab adges of 40 cm for XS and 60 cm XL if necessary.
