abstract
In this study, and for the first time, highly porous red mud-based geopolymer spheres were produced, through a very simple and scalable procedure, and used as lightweight aggregate in the synthesis of geopolymer composites. To further demonstrate the potential of this unexplored route, a comparison with composites containing expanded perlite and expanded vermiculite was also performed. The sample produced with 85 vol% of spheres showed the lowest geometric density (0.84 g/cm(3)) amongst the studied composites, coupled with a suitable compressive strength (1.0 MPa), low thermal conductivity (175 mW/m K), and excellent thermal stability after exposure to 1000 degrees C for 2h. The much lower production temperature (80 degrees C), compared with the commercial expanded aggregates (above 650 degrees C), and the reuse of significant amounts of bauxite residue (strategy aligned with the circular economy) enables the production of eco-friendly lightweight aggregates for the building sector.
keywords
FLY-ASH; THERMAL-PROPERTIES; METHYLENE-BLUE; RED MUD; CONCRETE; STRENGTH; REMOVAL; AMBIENT; PERLITE
subject category
Construction & Building Technology; Materials Science
authors
Alves, Z; Senff, L; Sakkas, K; Yakoumis, I; Novais, RM; Labrincha, JA
our authors
João António Labrincha Baptista
Full professor
Luciano Senff
Post-Doc Fellowship
Rui Miguel Novais
Assistant Professor
Zélia Ribeiro Alves
Junior ResearcherProjects
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
acknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MCTES (PIDDAC) . The authors would like to thank the project SMART-G (ERA-MIN/0001/2019) (DOI 10.54499/ERA-MIN/0001/2019) , sponsored by FCT.