Adaptive Educational Hypermedia Systems KBS Hyperbook System

A frame for bordering conduit access through a building floor has a rigid body portion and a lining of intumescent material on an interior surface of the rigid body portion. The intumescent material has sufficient expansion capacity to close off the opening through the frame under conditions which produce an intumescing of the lining. The rigid body portion itself is preferably made of a metallic material to enhance transfer of heat energy from the rigid body portion to the lining of the frame.