Improved concrete via upgraded oil shale ash

Sarit Nov 1, Shay Barak 2, Haim Cohen 1, 3 and Yaniv Knop 4, *

1 Department of Chemical Sciences, Ariel University, Ariel 40700, Israel.
2 Department of Chemical Engineering, Ariel University, Ariel, 40700 Israel.
3 Department of Chemistry, Ben Gurion University of the Negev University, Beer Sheva 84105, Israel.
4 Department of Civil Engineering, Ariel University, Ariel, 40700 Israel.
 
Research Article
World Journal of Advanced Engineering Technology and Sciences, 2024, 12(01), 411–420.
Article DOI: 10.30574/wjaets.2024.12.1.0064
Publication history: 
Received on 18 January 2024; revised on 23 May 2024; accepted on 26 May 2024
 
Abstract: 
Oil shale combustion produces large amounts of bottom ash residue that currently adds a storage problem due to a lack of efficient utilization modes. Oil shale is an abundant potential energy source, but its low calorific value and high ash content have limited its large-scale economic utilization as a fossil fuel. In Israel, there is only one industrial user which utilizes oil shale as fuel for process heat (steam production), producing so far more than a million tons of useless oil shale bottom ash (OSBA) in large piles under atmospheric conditions, raising environmental concerns. Previous studies show that OSBA can be a good substitute for cement due to its good pozzolanic reaction, in concrete without reducing strength, but its cementitious properties are limited. This study explores several chemical treatment methods to upgrade OSBA so that it can be used as a partial substitute for cement or aggregates in concrete. The study proved that the chemical-treated OSBA has improved reactivity and suitability as a concrete ingredient. Thus, upgrading OSBA could provide a productive use for the ash while reducing the need for cement production which is a polluting process. It could also cut off the environmental risks of long-term storage of large ash piles. The results may demonstrate a way for fruitful economic environmentally safe utilization of oil shale combustion as a fossil fuel. This also has the benefit of producing useful building materials without the need for large quarries while harnessing an abundant energy source with less waste.
 
Keywords: 
Oil Shales; Concrete; Hydration; Phosphoric Acid; Cement; Sustainability
 
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