TY - GEN
T1 - Effect of Type of Sand on the Flowability and Compressive Strength of Slag-Fly Ash Blended Geopolymer Mortar
AU - Hwalla, Joud
AU - El-Hassan, Hilal
AU - Assaad, Joseph J.
AU - El-Maaddawy, Tamer
AU - Bawab, Jad
N1 - Funding Information:
The authors gratefully acknowledge the financial support of the United Arab Emirates University under grant number 31N453. The technical support of the lab engineers and staff is also acknowledged.
Publisher Copyright:
© 2023, Avestia Publishing. All rights reserved.
PY - 2023
Y1 - 2023
N2 - This paper investigates the influence of the type of fine aggregates on the properties of slag-fly ash blended geopolymer mortar. Twelve mixes were prepared with two types of sand: desert dune sand (DS) and crushed dolomitic limestone sand (CS). Different alkaline activator solution-to-binder (0.50, 0.60, and 0.65) and binder-to-sand ratios (1:2, 1:3, and 1:4) were considered to analyze their effect on the performance of the geopolymer mortar. The properties under investigation included the amount of additional water needed to maintain a flow of 150 ± 2 mm and the 7-and 14-day compressive strengths. Experimental test results showed that an increase in fine aggregates content resulted in a higher additional water demand, regardless of the type of sand used. As a result, the mortar compressive strength decreased by up to 29% compared to mixes with the lowest binder-to-sand ratios (1:2 for DS mixes and 1:3 for CS mixes). An increase in the alkaline activator solution-to-binder ratio reduced the additional water needed to satisfy the target flowability but increased the overall liquid-to-binder ratio. Meanwhile, for optimum compressive strength, DS-based mixes comprised B:S and AAS/B ratios of 1:2 and 0.60, respectively, while those of CS-based mixes were 1:3 and 0.65, respectively. Compared to mixes made with CS, those incorporating DS required the addition of more water to maintain the flowability and experienced up to 81% loss in compressive strength; still, DS-based mixes achieved 14-day compressive strengths exceeding 28 MPa. The experimental findings advocate the use of DS as fine aggregates in the production of slag-fly ash blended geopolymer mortar to be utilized in various construction applications.
AB - This paper investigates the influence of the type of fine aggregates on the properties of slag-fly ash blended geopolymer mortar. Twelve mixes were prepared with two types of sand: desert dune sand (DS) and crushed dolomitic limestone sand (CS). Different alkaline activator solution-to-binder (0.50, 0.60, and 0.65) and binder-to-sand ratios (1:2, 1:3, and 1:4) were considered to analyze their effect on the performance of the geopolymer mortar. The properties under investigation included the amount of additional water needed to maintain a flow of 150 ± 2 mm and the 7-and 14-day compressive strengths. Experimental test results showed that an increase in fine aggregates content resulted in a higher additional water demand, regardless of the type of sand used. As a result, the mortar compressive strength decreased by up to 29% compared to mixes with the lowest binder-to-sand ratios (1:2 for DS mixes and 1:3 for CS mixes). An increase in the alkaline activator solution-to-binder ratio reduced the additional water needed to satisfy the target flowability but increased the overall liquid-to-binder ratio. Meanwhile, for optimum compressive strength, DS-based mixes comprised B:S and AAS/B ratios of 1:2 and 0.60, respectively, while those of CS-based mixes were 1:3 and 0.65, respectively. Compared to mixes made with CS, those incorporating DS required the addition of more water to maintain the flowability and experienced up to 81% loss in compressive strength; still, DS-based mixes achieved 14-day compressive strengths exceeding 28 MPa. The experimental findings advocate the use of DS as fine aggregates in the production of slag-fly ash blended geopolymer mortar to be utilized in various construction applications.
KW - compressive strength
KW - dune sand
KW - flow
KW - fly ash
KW - geopolymer
KW - limestone
KW - mortar
KW - slag
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U2 - 10.11159/iccste23.115
DO - 10.11159/iccste23.115
M3 - Conference contribution
AN - SCOPUS:85166190183
SN - 9781990800221
T3 - International Conference on Civil, Structural and Transportation Engineering
BT - Proceedings of the 8th International Conference on Civil, Structural and Transportation Engineering, ICCSTE 2023
PB - Avestia Publishing
T2 - 8th International Conference on Civil, Structural and Transportation Engineering, ICCSTE 2023
Y2 - 4 June 2023 through 6 June 2023
ER -