W. R. Grace Co.-conn.

Richard P Perito

Dennis M Hilton

Lawrence J Kindt

Improved sprayable gypsum-based fireproofing composition comprising a lightweight aggregate and a set retarding agent in an amount effective to delay the setting of said composition for at least 24 hours and preferably for at least 72-96 hours without causing the composition to swell or shrink or to cause a salt layer to form on the composition when it is spray-applied. The fireproofing composition can retain fluidity in conventional spray hoses overnight and yet is capable of being injected with a set accelerator, such as aluminum sulfate, on the next day or on a successive day when spray-applied onto a substrate.

Sprayable fireproofing composition

Sprayable fireproofing compositions for structural members such as steel columns are provided, as well as a method of applying multiple coatings thereof. The compositions comprise a Portland cement-based material, stucco, a high density aggregate and an accelerator. The compositions eliminate the long setting times typical of Portland cement-based materials, and improve the hangability thereof. The product is produced by dry blending a mixture of Portland cement, a high density aggreagte, stucco (calcium sulfate hemi-hydrate) and optionally, a stucco set retarder and shredded polystyrene aggregate. Upon the addition of water, sprayable slurries are formed which can be pumped to the point of application. An accelerator is added in close proximity to the point of injection. The slurries adhere to the structural member in the slurried state and after setting to provide excellent fire and heat protection. Because of the relative quick setting time of the slurry upon spray application, multiple coatings can be applied within the same working day.

Sprayable portland cement-based fireproofing compositions

Sprayable fireproofing compositions for structural members such as steel columns are provided, as well as a method of applying multiple coatings thereof. The compositions comprise a Portland cement-based material, stucco, and an accelerator. The compositions eliminate the long setting times typical of Portland cement-based materials, and improve the hangability thereof. The product is produced by dry blending a mixture of Portland cement, stucco (calcium sulfate hemi-hydrate) and optionally, a stucco set retarder and shredded polystyrene aggregate. Upon the addition of water, sprayable slurries are formed which can be pumped to the point of application. An accelerator is added in close proximity to the point of injection. Other additives may also be included, such as starch, adhesives and cement strength enhancers. The slurries adhere to the structural member in the slurried state and after setting to provide excellent fire and heat protection. Because of the relative quick setting time of the slurry upon spray application, multiple coatings can be applied within the same working day.

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Malden, MA, United States of America

Richard P Perito