Sure it's doable, it just makes the task that much more difficult. Plus you need to ensure there are no unintentional voids from the balls blocking the pour. Co

Sure it's doable, it just makes the task that much more difficult. Plus you need to ensure there are no unintentional voids from the balls blocking the pour. Code requires that they can't be within 1-2 inches of any steel or the surface of the concrete. Also, most designs assume a uniform cross section, and changing that greatly complicates the design method. And remember that the laborers doing this don't always understand (or care) about these sort of restrictions. It's usually cheaper and less risky to just use a lightweight mix, with injected air, if needed.