A burning bar or thermal lace will do the job cheap. You have to protect things tha might burn for a block or two arround. They burn through concrete and rebar fast. http://www.qccompany.com/burning_bar.htm
One of the first real jobs I had was working construction and the first site I worked on was a bank. The vault has rebar on four inch centers in all directions, tied at EVERY SINGLE JOINT. You know how I know it's tied at EVERY SINGLE JOINT.....because I was the poor guy that had to do the tyin'. And just for good measure the FDIC comes to inspect the cage before you form it up and pour concrete to make sure that it's tied at EVERY SINGLE JOINT. Well worth the $6.50/hr I was making.
