Title:
Study on Use of MSWI Fly Ash with Mainstream Supplementary Cementitious Materials
Author(s):
Kwangwoo Wi, Oguzhan Sahin, Kejin Wang, Yunsu Lee
Publication:
Symposium Paper
Volume:
362
Issue:
Appears on pages(s):
871-886
Keywords:
drying shrinkage; municipal solid waste incineration fly ash; supplementary cementitious materials
DOI:
10.14359/51742015
Date:
6/18/2024
Abstract:
The management of municipal solid waste incineration fly ash (MSWI FA) has become a critical issue as its generation increases rapidly along with the global population growth. In this study, MSWI FA was treated via water-washing, and then the untreated and water-treated MSWI FAs (RFA and WFA) were blended with mainstream supplementary cementitious materials (SCMs), including ground granulated blast-furnace slag (GS), silica fume (SF), and limestone powder (LS). The MSWI FASCMblends were used as a cement replacement in a mortar. The content of MSWI FAs was set at 10% (by weight of binder) for all mortar mixtures. The content of GS and LS was also set at 10%, while the SF content was 2.5%. Flowability, setting time, isothermal calorimetry, compressive strength, and free-drying shrinkage tests were performed. The results showed that mortars containing raw (untreated) fly ash (RFA) had reduced strength, whereas mortars containing water-treated fly ash (WFA) displayed comparable or even higher strength than the control mortar (made with 100% cement) after 28 days. While mortars containing RFA showed increased drying shrinkage, mortars containing WFA exhibited diminutive or no increase in drying shrinkage when compared to the control mortar. Based on the test results, the mixture with a cement:WFA:GS ratio of 80:10:10 was the optimal binder for concrete applications.