This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
The functions of fire-resisting materials are threefold:
1. To carry loads.
2. To protect all structural steel
3. To serve as noncombustible partitions or barriers.
The specific uses are, in general, the following:
*Note. By "effective depth of flat arch" is meant the depth from top of arch to bottom of beam.