Simply round: Cobiax void former modules for lightweight reinforced concrete slabs

With Cobiax you are investing in internationally patented and proven technology. Based on our extensive research, we have developed two exemplary product lines that are economical, ecological and universally usable for the construction of concrete slabs. Benefit from the enormous savings potential and many more advantages.

The Product Lines: Eco-Line and Slim-Line

Cobiax void former modules consist of fixed reinforcement steel elements with already integrated void formers made from one hundred percent recycled material. Available are two product lines, each with different void former sizes.


with spherically shaped void formers, specifically suitable
for wide span widths

> All Eco-Line Details



with flattened void formers, specifically suitable
for particularly slim concrete slabs

> All Slim-Line Details

Three simple steps to your Cobiax voided flat slab:


Determination of a suitable module and its placement according to project specific requirements

> All planning details


Delivery of ready-to-use void former modules to construction sites and pre-cast concrete works


Simple installation between top and bottom reinforcement – suitable for in-situ concrete or pre-cast component construction.

> All installation details


Easy combination with post-tensioning or concrete core activation and more.

Distinct product advantages

  • Save many tons of weight and costly materials
  • Construct concrete slabs easily, flat and with wide span widths
  • Overall structure optimization
  • Reduce dimensions of construction elements
  • Lower building costs without additional expenditures
  • Sustainable resource and climate savings


You will also benefit from:

  • More flexibility in layout design.
  • Full preservation or improvement of static performance .
  • Save up to 35 percent in concrete and up to 20 percent in reinforcement steel.
  • Minimize deflections and reduce strain for load bearing structures.
  • Improve future use of your construction object for conversions and restructuring.
  • Significant reduction of slab weight (1.4 – 4.8 k kN/m² dependent on size).
  • Reduce the overall structure weight.
  • Conduct your static calculations as usual.
  • Trouble-free installation of module system after delivery.




What void formers can do

Everything about Cobiax technology and its advantages

Our products in practice

How our clients cut down on material, weight and CO2