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Project Spotlight: Voided Slabs

Our Columbus BURG has been working on a medical research facility with six elevated levels of slab. The slabs involve a new unique feature called voided slabs. Read on to learn more about this innovative technology!


The oval balls are manufactured in Germany and contain a metal cage surrounded by plastic. Each cage contains 8 balls.


  • While no specific, formal training was required, our Columbus team reached out to others in the industry—including engineers who had implemented voided slabs into past projects—to obtain their input and guidance.
  • Our team performed a test placement to make sure our method was working properly before the voided slab pours.
  • It’s important to ensure the correct mix and that voids don’t float. This is achieved by doing two pours. The first placement is stopped at around 4” to lock in the lower section of void and cage. Once in place, the second half is poured.
  • Timing is key, and it’s necessary to make sure the initial pour sets before moving forward with pouring the rest of the slab.


Voided slabs use approximately 30% less concrete than a solid slab—making a concrete pour more environmentally friendly. Implementing voided slabs on our laboratory project reduces the vibration of the building without adding the additional height that a similar slab system would provide.

This technology is excellent for projects that require slab thickness without increasing the height of the building. In this case, the building is going to be used as a laboratory, and voided slabs were the right fit for the way the customer will employ the space.

Looking Forward

We’re excited to see how concrete technology continues to evolve and expect to see voided slabs in more projects and locations in the future. Thank you to our Columbus BURG for setting the stage and sharing more information with us about this exciting innovation!

Learn more about this project!