Performance of glass powder substituted slag based geopolymer concretes under high temperature

• Published in: Construction & building materials 2022-05, Vol.331, p.127318, Article 127318
• Main Authors: Derinpinar, Aslıhan Nida, Karakoç, Mehmet Burhan, Özcan, Ahmet
• Format: Article
• Language: English
• Subjects: Ambient curing; Geopolymer concrete; Glass powder; High temperature; Slag
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2022.127318

•The effect of GP substitution on the high temperature resistance of geopolymer concrete was studied.•5 groups of samples were subjected to 5 different temperatures.•GP improved the high temperature performance of geopolymer concretes.•Air cooling affected the samples less negatively than water cooling. Geopolymer concretes provide advantages in terms of recycling waste materials. Geopolymer concretes are advantageous in terms of both limiting the use of Portland cement and recycling waste materials. In this study, 5 different geopolymer concrete mixture groups were prepared by replacing slag with 0.5%, 10, 15 and 20% by weight glass powder (GP). Geopolymer concrete samples prepared by using 12 M sodium hydroxide solution as an alkali activator were cured in the laboratory environment. The samples, which completed their curing periods, were kept at 150, 300, 450, 600 and 750 °C temperatures for 1 h. Compressive strength, weight change and sorptivity values of these samples were determined. These results were interpreted together with the visual inspections and microstructure analyzes (SEM and EDS) of the samples. As the GP substitution rate increased, the mechanical properties of geopolymer concretes decreased. However, GP improved the performance of geopolymer concretes exposed to high temperatures. Cooling in air affected the samples less negatively than cooling in water. While the Ca/Si ratios of the samples decreased at 450 °C and above, the Si/Al ratio increased.