It’s unlikely that thermite and its derivatives would be used to demolish a building on their own. My speculation is that thermite could be placed inside a drilled hole in a steel beam, either from above or from the side of the target beam. Thermite’s products are a mix of molten iron and aluminium oxide, and high temperatures over 1000 C, as is stated in the patent[10]. However the logical inference is that thermite could be used on some core columns, with the remainder broken at some point with RDX linear cutter charges. The thermate could be used to weaken the structure, with relatively few linear cutter charges needed to initiate the building collapse. The only real advantage of using thermate over RDX for cutting beams, is that thermate burns rather than explodes (and therefore does not create a loud explosion).