Characterization of Qatar Municipal Waste Fly Ash and Its Reuse in Cementitious Composites


Genç Tokgöz D. D. , Ozerkan N. G. , Antony S.

2nd International Conference on Green Chemical Engineering Technology (GCET2015), Melaka, Malaysia, 24 - 25 November 2015, pp.18-19

  • Publication Type: Conference Paper / Summary Text
  • City: Melaka
  • Country: Malaysia
  • Page Numbers: pp.18-19

Abstract

Fly ash can be defined as fine particulate matter captured from the stack gases of coal fired power plants or incinerators. It is usually called as coal fly ash if it is from coal power plants, and called as municipal fly ash if it is produced from combustion of municipal wastes. Approximately 60 tonnes of fly ash is generated daily from Domestic solid waste management center incinerator of Qatar(DSWMC) as a waste by-product material. As municipal fly ash is considered as hazardous waste, a lot of money has been spent for its transportation and disposal into landfills. The objective of this study was to determine chemical and physical properties of municipal fly ash and investigate its beneficial use in cement mortar.


Characteristics (physical and chemical) of municipal FA depends many factors in the combustion process i.e. main types of raw materials, combustion equipment, combustion temperature and air pollution control technology. Therefore characteristic of municipal FA is unique for each combustion facility, and must be determined separately. Chemical composition of municipal FA in this project is found significantly different than those reported in the literature. Very low silica content is probably the reason for poor strength activity index (SAI) with Portland cement. High lime content (65.7%) may be beneficial and contribute to the cementitious properties, however very low amount of silicates, aluminates and iron-oxide may restrict the production of their hydrates. Very high SO3 content (8.67% ) will probably cause retarded setting time and lead volume instability and thus loss of durability. Excessive levels of Cl (19.4%) may encounter some problems. High alkali content (Na2O+0.658*K2O) of municipal FA may probably cause alkali-silica reaction and results in disintegration of mortar.

Fly ash can be defined as fine particulate matter captured from the stack gases of coal fired power plants or incinerators. It is usually called as coal fly ash if it is from coal power plants, and called as municipal fly ash if it is produced from combustion of municipal wastes. Approximately 60 tonnes of fly ash is generated daily from Domestic solid waste management center incinerator of Qatar(DSWMC) as a waste by-product material. As municipal fly ash is considered as hazardous waste, a lot of money has been spent for its transportation and disposal into landfills. The objective of this study was to determine chemical and physical properties of municipal fly ash and investigate its beneficial use in cement mortar.


Characteristics (physical and chemical) of municipal FA depends many factors in the combustion process i.e. main types of raw materials, combustion equipment, combustion temperature and air pollution control technology. Therefore characteristic of municipal FA is unique for each combustion facility, and must be determined separately. Chemical composition of municipal FA in this project is found significantly different than those reported in the literature. Very low silica content is probably the reason for poor strength activity index (SAI) with Portland cement. High lime content (65.7%) may be beneficial and contribute to the cementitious properties, however very low amount of silicates, aluminates and iron-oxide may restrict the production of their hydrates. Very high SO3 content (8.67% ) will probably cause retarded setting time and lead volume instability and thus loss of durability. Excessive levels of Cl (19.4%) may encounter some problems. High alkali content (Na2O+0.658*K2O) of municipal FA may probably cause alkali-silica reaction and results in disintegration of mortar.