Archived
This content is available here strictly for research, reference, and/or recordkeeping and as such it may not be fully accessible. If you work or study at University of Kentucky and would like to request an accessible version, please use the SensusAccess Document Converter.
From Ash Pond to Concrete: A Two-Step Treatment for Enhancing Reactivity of Reclaimed Ashes
Description
The closure of coal-fired power plants has led to a shortage of fly ash for concrete, increasing interest in alternative Supplementary Cementitious Materials (SCMs). Reclaimed or harvested fly ash represents a promising SCM, but often fails to meet ASTM specifications due to impurities, variable composition, and low reactivity. This study highlights a two-phase evaluation of harvested coal ash from a local ash pond in Illinois. The first phase characterized ashes from different depths and locations based on chemical composition and pozzolanic reactivity. The second phase focused on a novel two-step treatment consisting of magnetic separation and mechanical grinding. On average, magnetic separation increased the ASTM C1897 7-day R3 heat from 120 J/g to 190 J/g, while subsequent grinding further increased the R3 heat to 380 J/g for 8 unique samples. Our findings show reclaimed fly ash post-treatment can be a viable substitute for conventional fly ash, while reducing the environmental impacts of storing these ashes in landfills.
From Ash Pond to Concrete: A Two-Step Treatment for Enhancing Reactivity of Reclaimed Ashes
Lexington, Kentucky
The closure of coal-fired power plants has led to a shortage of fly ash for concrete, increasing interest in alternative Supplementary Cementitious Materials (SCMs). Reclaimed or harvested fly ash represents a promising SCM, but often fails to meet ASTM specifications due to impurities, variable composition, and low reactivity. This study highlights a two-phase evaluation of harvested coal ash from a local ash pond in Illinois. The first phase characterized ashes from different depths and locations based on chemical composition and pozzolanic reactivity. The second phase focused on a novel two-step treatment consisting of magnetic separation and mechanical grinding. On average, magnetic separation increased the ASTM C1897 7-day R3 heat from 120 J/g to 190 J/g, while subsequent grinding further increased the R3 heat to 380 J/g for 8 unique samples. Our findings show reclaimed fly ash post-treatment can be a viable substitute for conventional fly ash, while reducing the environmental impacts of storing these ashes in landfills.
