From the desk of Alex Vondeling.
I’ve heard of voided concrete, but not yet used in any project. This product by Cobiax USA Inc seems like a pretty intriguing green option. I would assume it would not cost more and perhaps less than conventional structural concrete systems. I checked with CVM (structural engineers). While they are familiar with voided concrete they have not used it in any of their projects – perhaps since steel and wood seem to be far more common structural materials.