At the start of this video is a clip from the National Geographic hit piece where they place regular Thermite around a steel column.
I recommend repeating this same experiment but with the Thermite, or rather a Thermate derivative (one of the enhanced forms of Thermite actually detected at ground zero), placed INSIDE THE STEEL COLUMN. Try this with the column end open and then sealed with either concrete or some other material. I think you will find the results will be rather different.
National Geographic should not have done this experiment since it gives people ideas as to how the real attacks were staged. After all we KNOW, from the forensic evidence referred to later in the clip, that Thermate and Nano-Thermites were used upon the Twin Towers and WTC7. The only remaining question is how.