Product Detail


Polyethylene or polypropylene plastic voids designed to displace non-working dead loads while maintaining biaxial strength in elevated concrete slabs. Suitable for multi-residential, commercial and industrial applications.








Cobiax® is a system of hollow plastic voids, made from high density polyethylene or polypropylene, which are placed between the upper and lower steel reinforcement cages surrounding a concrete slab. Product therefore displaces concrete which has no structural benefit, optimising the slab's thickness and building material volume.

Product reduces weight of slabs by up to 35% (compared to a solid slab of the same bearing capacity), while maintaining the same biaxial and flexural strength. Product can also increase dimensions of the building's vertical bearing elements (up to 18m spans without beams are achievable) which may decrease structural materials required, such as support columns. The reduction in dead weight also facilitates savings in foundation loads, for example fewer piles or length of piles.

System integrates specific reinforcing steel cages with void formers to speed erection and simplify handling of void formers. Product is suitable for elevated concrete slab construction where long spans without beams are required. Suitable for in-situ cage modules (CBCM) as well as semi pre-cast concrete panel applications (CBSP). Scraps from manufacturing of other products are reprocessed as raw material for plastic void manufacture. This system has a Green Star Office Design and Interiors.


Information last verified 01/03/11

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