According to NIST ( National Institute of Standards and Technology) that was funded by Congress to investigate the collapses, WTC 1 fell in 11 seconds and WTC 2 fell in 9 seconds.
Incorrect. Here is the FAQ page from NIST regarding the collapse times.
FAQs - NIST WTC Towers Investigation
To summarize, the times you quote are when the first exterior panels hit the ground after collapse initiation, NOT for the total collapse. There are videos that support this.
11. How could the WTC towers collapse in only 11 seconds (WTC 1) and 9 seconds (WTC 2)—speeds that approximate that of a ball dropped from similar height in a vacuum (with no air resistance)?
NIST estimated the elapsed times for the first exterior panels to strike the ground after the collapse initiated in each of the towers to be approximately 11 seconds for WTC 1 and approximately 9 seconds for WTC 2. These elapsed times were based on: (1) precise timing of the initiation of collapse from video evidence, and (2) ground motion (seismic) signals recorded at Palisades, N.Y., that also were precisely time-calibrated for wave transmission times from lower Manhattan (see NIST NCSTAR 1-5A).
As documented in Section 6.14.4 of NIST NCSTAR 1, these collapse times show that:
“The structure below the level of collapse initiation offered minimal resistance to the falling building mass at and above the impact zone. The potential energy released by the downward movement of the large building mass far exceeded the capacity of the intact structure below to absorb that energy through energy of deformation.
Since the stories below the level of collapse initiation provided little resistance to the tremendous energy released by the falling building mass, the building section above came down essentially in free fall, as seen in videos. As the stories below sequentially failed, the falling mass increased, further increasing the demand on the floors below, which were unable to arrest the moving mass.”
In other words, the momentum (which equals mass times velocity) of the 12 to 28 stories (WTC 1 and WTC 2, respectively) falling on the supporting structure below (which was designed to support only the static weight of the floors above and not any dynamic effects due to the downward momentum) so greatly exceeded the strength capacity of the structure below that it (the structure below) was unable to stop or even to slow the falling mass. The downward momentum felt by each successive lower floor was even larger due to the increasing mass.
From video evidence, significant portions of the cores of both buildings (roughly 60 stories of WTC 1 and 40 stories of WTC 2) are known to have stood 15 to 25 seconds after collapse initiation before they, too, began to collapse. Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely.
As far as your contention that the WTC core wasn't rebar encased in concrete. Allow me to remind you that it was a 60 to 40 ration concrete to steel.
Where did you get that information from? The following site lists 200,000 tons of steel for the WTC COMPLEX (not just WTC1 and WTC2). The site also lists 425,000 cubic yards of concrete for the WTC COMPLEX (not just WTC1 and WTC2). Do you know how much concrete was used in the bath tub that surrounds the buildings? How about the foundations? There was no rebar encased concrete in the core. This was garbage started by Christopher Brown years ago and has since been debunked. If you would like to go over the physical impossibility of there being a concrete core surrounding the 47 core columns, I will be happy to show you.
The World Trade Center — Facts and Figures
I will take your word that they found engine pieces from the wreckage of WTC 1 and 2 but they found nothing at the Pentagon...they claim that the engines melted. I do not buy it.
What about the "small hole" in the Pentagon claim? I have provided you with evidence that shows this to be incorrect.
How about the paper by James Millette that refutes the findings of Thermite in the dust? Harrit's paper is a joke. Harrit's paper declares that further studies are needed, but that never happened. People have asked him for samples of his dust, but he refuses. He says it's not paint but only compared it to ONE types of primer paint. There were two types used in the towers. So many things wrong with this paper. Care to discuss?
The hole for the Pentagon.....
See my statement above.