- Author
- Ryan, J. V.
- Title
- Study of Gypsum Plasters Exposed to Fire.
- Coporate
- National Bureau of Standards, Washington, DC
- Journal
- Journal of Research of the National Bureau of Standards. C. Engineering and Instrumentation., Vol. 66C, No. 4, 373-387, October-December 1962
- Report
- Paper 66C4-113
- Keywords
- gypsum | plaster | fire tests | thermal properties | fire endurance tests | aging (materials) | furnaces | data analysis
- Identifiers
- building elements; thickness; aggregates; temperature
- Abstract
- Experimental results are reported from a study in which small gypsum plaster speciemns were exposed to controlled fire similar to those to which large building elements have been subjected in tests by a recognized standard method. The small specimens were tested without either structural load or restraint. Their fire performances were judged on time to a temperature rise criterion. The results were analyzed to determine the effects on fire performance of variation of mix ratio, aggregate type and density, duration of aging, and relative humidity of the ambient in which the specimens were aged. Mix ratio and aggregate density, over the ranges normally used, had little effect, if any, on fire performance. The times to temperature rise for perlite and verimiculite aggregate plasters were essentially equal, but shorter times were observed for sanded plasters. Duration of aging and relative humidity of the ambient were observed for sanded plasters. Duration of aging and relative humidity of the ambient had a significant effect only for short aging periods and very high relative humdiity conditions. Estimates of thermal properties of gypsum plasters at elevated temperatures were derived from the data. These estimates should be useful for predicting fire endurances of building elements involving gypsum plaster.