TY - JOUR
T1 - Recycling of red mud and flue gas residues in geopolymer aggregates (GPA) for sustainable concrete
AU - Qian, Lan Ping
AU - Ahmad, Muhammad Riaz
AU - Lao, Jian Cong
AU - Dai, Jian Guo
N1 - Funding Information:
The authors would like to acknowledge the financial support received from NSFC/RGC Joint Research Scheme ( N_PolyU542/20 ), Hong Kong RGC General Research Fund (No. 15223120 ), The Hong Kong Polytechnic University through the Research centre for Resources Engineering towards Carbon Neutrality (No. BBC7 ) and the Hong Kong Polytechnic University Ph.D. studentship, awarded to the first author.
Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/4
Y1 - 2023/4
N2 - This study proposed simultaneous utilization of red mud (RM) and flue gas residues (FGR) as a partial replacement of traditional precursors and energy-intensive activators. Reaction mechanisms of geopolymer pastes were investigated through isothermal calorimetry, X-ray diffraction, thermogravimetry and infrared spectroscopy, by varying the dosage of RM (40%) and FGR (24%, 32%). Results showed that use of RM and FGR as a replacement of FA and commercial activator had a limited influence on the compressive strength. RM and FGR participated in reaction at a slower rate. After optimization, heat-cured FGR0.32 mix was selected to manufacture geopolymer aggregates (GPA). Engineering properties, cost analysis and environmental impact of GPA were evaluated. Natural aggregates (NA) were replaced by GPA at replacement levels of 25%, 50%, 75% and 100% by volume to prepare concrete. GPA concrete with 25% and 100% replacement level could achieve the 94.6% and 86.6% of NA concrete strength respectively at 28 days age.
AB - This study proposed simultaneous utilization of red mud (RM) and flue gas residues (FGR) as a partial replacement of traditional precursors and energy-intensive activators. Reaction mechanisms of geopolymer pastes were investigated through isothermal calorimetry, X-ray diffraction, thermogravimetry and infrared spectroscopy, by varying the dosage of RM (40%) and FGR (24%, 32%). Results showed that use of RM and FGR as a replacement of FA and commercial activator had a limited influence on the compressive strength. RM and FGR participated in reaction at a slower rate. After optimization, heat-cured FGR0.32 mix was selected to manufacture geopolymer aggregates (GPA). Engineering properties, cost analysis and environmental impact of GPA were evaluated. Natural aggregates (NA) were replaced by GPA at replacement levels of 25%, 50%, 75% and 100% by volume to prepare concrete. GPA concrete with 25% and 100% replacement level could achieve the 94.6% and 86.6% of NA concrete strength respectively at 28 days age.
KW - Flue gas residues (FGR)
KW - Geopolymer aggregate concrete (GAC)
KW - Geopolymer aggregates (GPA)
KW - Mechanical properties
KW - Red mud (RM)
UR - http://www.scopus.com/inward/record.url?scp=85147370760&partnerID=8YFLogxK
U2 - 10.1016/j.resconrec.2023.106893
DO - 10.1016/j.resconrec.2023.106893
M3 - Journal article
AN - SCOPUS:85147370760
SN - 0921-3449
VL - 191
JO - Resources, Conservation and Recycling
JF - Resources, Conservation and Recycling
M1 - 106893
ER -