Holedeck

Description

The Holedeck is similar to a Waffle slab, with the only difference that there are holes in the ribs. It is also cast in situ and can be post tensioned. It carries in two directions and is thus more efficient for a square room layout. Holedecks are significantly weaker against shear than waffle slabs due to the holes, so the structure needs to be altered to perform well against punching. The economic span lays between 5 and 12 m. Because it is cast in situ, it can easily be made continuous to reduce deformations.

Holedecks perform well in fires and can withstand fires for up to 120 min.

The flexibility on site is low for a cast in situ slab, because it uses standardised formwork elements, so no sudden changes can be done, also the geometric flexibility suffers from the use of formwork elements. The big advantage from the holes is the easy integration of building systems, all the cables and tubes can pass through the holes. The complexity of fabrication is high due to all the formwork elements that need to be either produced or at least transported to the site. The installation on the other hand is average, when seen over all slabs, and easy, when compared to other cast in situ slabs. That is another place where the formwork elements shine, despite that, one still needs to install all the reinforcement and make sure the concrete distributes nicely. The construction speed is low due to the complex geometry, also installing and uninstalling the formwork elements takes some time.

As in most concrete floors, vibration is not a concern due to the large weight.
The slenderness l/h lays between 20 to 22, this is similar to the Waffle Slab.

Database

Floor type			Holedeck
Materials			concrete_reinforcing steel_prestressed strands
Description			similar to two-way waffle slab but with holes in it
Way of carrying	Does the main span carry in one or two directions?		two way slab
Span width low [m]	Economically possible		5
Span width high [m]	Economically possible		12
Additional measures when installing			special formwork_propping up
Prefab?	Is prefab possible?		no
Continous slab?	Can you build the slab with supports in middle of the slab?		yes
Building systems integratable?	Can buildings systems be included into the slab itself?		yes
Fire	Fireresistance without costly measures [min]		120
Substructure	Certain prerequisites necessary?		no
Prone to vibration			no
Environment	General classification including formwork	1 to 5 terrible to very good	3
Construction time	Time on site	1 to 5 very slow to very fast	2
Flexibility	Average of the next two	1 to 5	3
Flexibility on site	How flexible is the system to spontaneous changes on site?	1 to 5 terrible to very good	3
Flexibility geometry	How good can you adapt the slab to complex geometries?	1 to 5 not at all to very easy	3
Complexity	Average of the next two	1 to 5	3
Complexity fabrication	Complexity of floor itself.	1 to 5 very complicated to very simple	3
Complexity installation	Complexity installation on site	1 to 5 very complicated to very simple	3
Slenderness l/h 3kPa	Applied load (without selfweight)	Residential building	22
Slenderness l/h 4kPa	Applied load (without selfweight)	Office building	20
Weight [kN/m3]	per m2 and total height of slab		5
Embodied energy [MJ/m3]	per m2 and total height of slab		1041

References

General information:

https://holedeck.com/

Span width:

5 - 12m (https://holedeck.com/en/productos-holedeck/)

Fire resistance:

up to 120min (https://holedeck.com/en/productos-holedeck/)

Slenderness:

l/h=22 for 3kPa, l/h=20 for 4kPa. (https://holedeck.com/)

Weight:

Calculations

Embodied energy:

Calculations

Photo Source:

https://holedeck.com/