- Author
- Mitchell, N. D.
- Title
- Fire Tests of Columns Protected With Gypsum.
- Coporate
- National Bureau of Standards, Gaithersburg, MD
- Journal
- Journal of Research of the National Bureau of Standards, Vol. 10, 737-755, June 1933
- Report
- RP 563,
- Keywords
- columns | gypsum | fire tests | plaster
- Identifiers
- steel cramps or ties; unplastered block coverings
- Abstract
- Fire tests of six building columns protected with gypsum have been made to supplement previous fire tests of columns similarly protected. These tests demonstrate the importance of some form of positive bond, such as steel cramps or ties, to hold unplastered block coverings in place. Block coverings with sanded gypsum plaster finish shrank less than the unplastered blocks and remained in place during the fire until the columns had failed. The plaster applied to block coverings increased the fire resistance in greater proportion than the ratio of the squares of resulting net thicknesses of covering outside of the steel.