I've also seen automatic closure devices disabled or removed so that the door won't be pulled closed.
Below is a common solution to this problem: Notice the two small devices near the top of the doors and along the walls flanking the doors. These are electomagnetically operated door holders. They are deactivated by a switch on the wall so that the doors can be closed, and they are automatically deactivated by the Fire Alarm System in the event of a fire.
Teach your students and staff about Fire Doors and make sure that they don't disable or bypass this valuable feature just for the convenience of reducing door opening and closing tasks. If the door is mechanically loud and clunky, look at having the mechanism(s) repaired or replaced; and teach your crew how to go through a door stealthly, like a ninja! Not everything requires brute-force!