improving concrete sustainability

One System. Many Greener Solutions.


Everything you like about concrete and a lot less of the volume you don’t need.

Voided concrete slabs enable many ways to reduce concrete’s carbon footprint and generally improve a project’s sustainability.

The traditional use of concrete, with its high consumption of environmental resources, can be greatly improved with the implementation of efficient voided building methods. This results in high weight-bearing slab construction, that not only saves material (concrete) but also enables larger spaces to be spanned at the same weight. This was the design idea behind the development of voided concrete slab system.

The benefits of voided slabs clearly extend into all areas of triple-bottom-line consideration, having proven itself in a diverse collection of high-profile projects on several continents. Case studies summarized here will highlight the ways in which CobiaxUSA has made a real difference.



40% Fewer columns without beams


Safe, Reliable Performance. — Voided slabs enhance the most comfortable and secure building material in the world, concrete.

  • Flexible layout

  • Secure construction

  • Earthquake resistant

  • Thermally efficient

  • Aesthetically pleasing

Advances in building technology should never be at the expense of safety. That’s why many years of research have gone into voided concrete slab technology. These voided flat plate slab solutions fulfill the most stringent international standards, and due to the reduction in the weight of the slabs, the risks of sudden loads are reduced (e.g. during an earthquake). CobiaxUSA quality assurance guidelines set standards for plastic-based building materials. CobiaxUSA systems help to ensure permanent structural stability for many generations to come. Construction companies, engineers, architects, and owners can be assured that they will benefit from the numerous advantages of voided concrete slab systems, without increasing risk.

Increased Earthquake Safety According to the National Institute of Building Sciences, earthquakes generate internal forces within buildings and lightweight construction with less mass is typically an advantage in seismic design.


20% Less carbon in the environment


Lower Impact, Longer Life CobiaxUSA systems can greatly reduce carbon impacts by reducing material volumes, reuse, and transport.

  • Resource-efficient

  • Reduces carbon impact

  • Reduces waste

  • 100% recycled void-formers

  • More energy efficient building use

  • Can benefit from local resources

The use of plastic and voiding material replaces at least 25 – 30% of the concrete used for conventional building methods. This greatly reduces the carbon emissions during cement production and the amount of concrete ultimately required in the slab. The void formers themselves are made of 100% recycled plastic.  Further, the construction remains stable over several decades and centuries.

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Truckload Comparison 1.png

35% Less weight impact on costs


Reduced Material & Labor CobiaxUSA systems can eliminate columns and reduce substantial weight in floors and in the foundation.

  • Lower floor-to-floor heights without beams

  • Life-cycle energy savings

  • Simplified concrete formwork

  • Compliments post-tensioning systems

  • Less concrete and reinforcing steel

  • Improves resiliency

The required volumes of concrete that need to be transported will be reduced by about 30%, as does the vehicle load. The bearing components of the structure can be made lighter and more elegant due to the reduction of the load to be carried. When voided concrete slabs and post-tensioning are combined, the required post-tensioning is ~25% less than a comparable solid slab. Thanks to the lighter design of the building itself, the available net space also increases; this, in turn, leads to an increase in the possible returns.


  • Reduced vertical loads reduce column and foundation sizes and earthquake reinforcing.

  • Flat plate design minimizes costly/time consuming vertical formwork, a major cost component.

  • Reduce weight up to 35% from that typical with solid slabs.

  • Expect up to 15% less load on building foundations.

  • Gain design freedom from greater floor planning flexibility.

  • Achieve up to 65 ft span length.

  • Require up to 40% fewer columns.

  • Resource efficiency through reduced concrete and reinforcement throughout.

  • When voided concrete slabs and post-tensioning team up, the required post tensioning is 25% less than for solid slabs.

  • Lower floor-to-floor heights reduce vertical costs.

  • Achieve more effective retrofitting.