What caused the concrete to fuse around the floor studs at Ground Zero?

The video that was here had an autoplay problem, All of the videos on this blog were playing simultanously. I am trying to fix the problem...G%  

Here's a link to my blog...

Miracle Truck and Mysterious Concrete Globs at Ground Zero.

Evidence of temperatures hot enough to melt concrete and steel are everywhere you look in this video footage, yet there also places where you would expect maximum damage, that look like nothing happened. The Coca Cola truck sitting by the skeleton of Tower 2 looks normal, while in other places there are cars and trucks with melted engine blocks and missing glass that are blocks away from the ruins of the buildings. 

This appears to be the end part of a floor truss with part of the floor pan and the end of the zig zag bar that re-enforces it. There was 4 inches of concrete poured over the top of the studs. The question is...how did the concrete floors disappear and why is there fused concrete bonded to the studs and the end piece. My first guess is that the concrete was suspended in plasma and was possibly attracted to the iron which acted as a heat sink.

Kudos to WTC911demolition for posting this...

 

                                                A clip from...

                     9/11 fires

WTC911demolition

Published on Apr 14, 2012

 extended raw footage from two cameras (cut at 22:18) from about 11:20 am to afternoon sometime.. 911datasets.org release 25, 42A0113 - G25D23 some available in release 14, WNBC Dub3
 Lenny Mulhern

 https://www.youtube.com/watch?v=JmVRW...