When steel gets very hot, does it explode and fragment? Can air fire powderise solid concrete?

Question

Watch this:

http://www.youtube.com/watch?v=Bx1E2B5oAEs

Apparently, the media has told us that when steel framed
buildings get very hot, they EXPLODE VIOLENTLY just like
in a controlled demolition, so that all their steel columns tear
apart over dozens of floors (even floors that were not on fire
can even explode??? Why?) converting hundreds of
thousands of tons of steel into shredded metal or red hot
motel metal for over 6 weeks, and turning very strong concrete
floors completely into fine powder EXACTLY like a well
planned controlled demolition!

Powerful stuff, this "jet fuel" (or kerosene); even just a few
small fires on a few levels, can TOTALLY LEVEL giant
skyscraper buildings! Take a look at the evidence that air
fires, fed by jet fuel, can completely pulverise skyscrapers,
without the need for any explosives!

Look at this proof that jet fuel air fire can MELT STEEL!

Amazing!

http://www.youtube.com/watch?v=Qa7PN-8T2VY

http://www.truth911.net

Answer 1

Thanks for 2 more points on the same question, different catagory. The steel does not explode. Concrete when heated rapidly can explode from the expansion of the moisture in it.
And I have seen this video several times. Cool stuff.