Accession Number PB2013-103595
Title Identification of Potential Concerns Associated with FDOT Use of Ammoniated Coal Fly Ash.
Publication Date Dec 2012
Media Count 136p
Personal Author C. Y. Wu J. Schert T. Townsend
Abstract The objectives of the project were to identify potential concerns of using ammoniated fly ash in concrete and to provide recommendations for appropriate limits based on considerations of worker health and safety. A series of laboratory-scale exposure and leaching experiments with fly ash of different ammonium contents added into concrete were carried out to determine the mass transfer rates of ammonia/ammonium release from concrete to water/air. The measured mass transfer rates were applied in the semi-infinite diffusion model to assess maximum potential exposure for typical concrete handling scenarios. In overall consideration of modeling results, industry assessment, and results of previous research, a threshold of ammonium concentration in fly ash of 100 ppm was proposed for normal working conditions. However, the research team also recommended that appropriate safety protocols should be evaluated for some working conditions with poor ventilation.
Keywords Ammonia
Cements
Concretes
Environmental exposure
Florida
Florida Department of Transportation(FDOT)
Fly ash
Highways
Leaching
Occupational safety and health
Roads
Ventilation
Work environment


 
Source Agency Department of Transportation
NTIS Subject Category 50C - Construction Equipment, Materials, & Supplies
50A - Highway Engineering
43G - Transportation
68G - Environmental Health & Safety
Corporate Author Florida Univ., Gainesville. Coll. of Engineering.
Document Type Technical report
Title Note Final rept.
NTIS Issue Number 1310
Contract Number BDK75-977-43

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